It looks like you are confusing what's needed between an external script (executed from outside the sage 100 desktop) and an internal script (triggered by a button added via Custom Office or a table or UI event script).

If you look at a given object's page on the online file layouts and object reference, you should see that if they deal with batches, they should inherit SY_BatchDataEntry which is detailed on this page.

http://help-sage100.na.sage.com/2019/FLOR/#Object_Reference/BaseSystem/SY_BatchDataEntry.htm

The above object includes a SelectNewBatch method which can be used to mark a newly created batch as private by passing "Y" in the second argument. I do not know if this can be used on existing batches,

The above object also includes a GetBatchHandle method which if you pass the UI object handle of the current object, it should return the handle to the batch manager object which i assume would be SY_BatchManager_Bus and should be on the current batch record, at that point i would think you would just need to use SetValue on the PrivateBatch$ field but i'm not sure if that will require a Write method as well, and if it does, i'm not sure if it will require being followed up with a SetKey to get the batch record back in an edit state for the entry task.

Just following up, the SelectNewBatch does not seem to work on existing batches and i could not get GetBatchHandle to work with current UI handle.

One way to do this is with the following.

I do not know for sure what kind of effect this might have on other standard functionality within the session this occurs under but it does achieve what you want.

If oBusObj.BatchEnabled = 1 Then
    oBatch_Bus = 0 : oBusObj.GetValue "coBatch", oBatch_Bus
    If oBatch_Bus > 0 Then
        Set oBatch_Bus = oSession.AsObject(oBatch_Bus)
        PrivateBatch = "" : oBatch_Bus.GetValue "PrivateBatch$", PrivateBatch
        If PrivateBatch <> "Y" Then
            oBatch_Bus.SetValue "PrivateBatch$", "Y"
            oBatch_Bus.Write
            oBatch_Bus.SetKey oBatch_Bus.GetKey() ' I do not know for sure whether this line is really needed but it makes sure to put the batch back into an edit state after the Write.
        End If
        Set oBatch_Bus = Nothing
    End If
End If

Just following up, the SelectNewBatch does not seem to work on existing batches and i could not get GetBatchHandle to work with current UI handle.

One way to do this is with the following.

I do not know for sure what kind of effect this might have on other standard functionality within the session this occurs under but it does achieve what you want.

If oBusObj.BatchEnabled = 1 Then
    oBatch_Bus = 0 : oBusObj.GetValue "coBatch", oBatch_Bus
    If oBatch_Bus > 0 Then
        Set oBatch_Bus = oSession.AsObject(oBatch_Bus)
        PrivateBatch = "" : oBatch_Bus.GetValue "PrivateBatch$", PrivateBatch
        If PrivateBatch <> "Y" Then
            oBatch_Bus.SetValue "PrivateBatch$", "Y"
            oBatch_Bus.Write
            oBatch_Bus.SetKey oBatch_Bus.GetKey() ' I do not know for sure whether this line is really needed but it makes sure to put the batch back into an edit state after the Write.
        End If
        Set oBatch_Bus = Nothing
    End If
End If

David, you are AWESOME!

There is NO way I could have figured that out.

Ok, here is my follow-up.  Do you or anyone provide any sort of training in scripting?  I know Alnoor did one or two before Summit last year but I missed them.  I would love to know more about scripting since the possibilities available can truly be endless.

Thanks again for this.

I haven't, nor do i really plan on doing any formal training but i have numerous posts on here that you should find helpful. In one, i go quite in depth regarding some fundamentals which was a response to a similar question as yours.

There is a Sage U course for the BOI.

There is also a scripting.docx document that covers some fundamentals as well. 

/cfs-file/__key/communityserver-discussions-components-files/97/ScriptingPlus_2D00_v170.docx 

Here are some KB links.

Customizer Variables. 

https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=43033

MsgBox Warning. 

https://support.na.sage.com/selfservice/viewdocument.do?noCount=true&externalId=82673

The online File Layouts & Object Reference is a great resource as well.

http://help-sage100.na.sage.com/2019/FLOR

Alnoor, Steve, Elliott, and Kent also have many examples that they have posted on here as well.

Alnoor also had some examples on one of his blogs, can't remember whether it was the xkZero one or not. I did find the following links.

http://erpappsblog.com/line-item-discount-calculations-scripting-tip-for-sage-100-erp/

http://erpappsblog.com/script-to-prevent-dup-customer-names/

http://erpappsblog.com/how-to-use-scripting-to-require-additional-fields-on-a-screen/

http://erpappsblog.com/use-scripting-to-change-all-shipping-warehouses-on-an-order/

There also was a Deep Dive Into Customizer video series that had 8 videos. However, i don't know if they are still publicly available, may need to reach out to sage to see if they are still available. https://www.sagecity.com/support_communities/sage100_erp/f/sage-100-personalization-customization-and-productivity-tools/38612/deep-dive-into-customizer-for-mas-90-and-200-v-4-3

There are also several videos on hosting sites like youtube that you can find with any search engine, just search for "sage 100 scripting" and you should get some results.

More useful links for reading.

https://www.sagecity.com/support_communities/sage100_erp/f/sage-100-business-object-interface/126277/is-there-any-way-to-use-the-boi-on-modules-not-created-directly-by-sage/336706#336706 

https://www.sagecity.com/support_communities/sage100_erp/f/sage-100-personalization-customization-and-productivity-tools/125651/udf-week-date-calculation-using-a-vb-script/335436#335436

https://www.sagecity.com/support_communities/sage100_erp/f/sage-100-business-object-interface/124232/boi-setvalue-clear-error-handling/335224#335224

That should be enough to get you started.

David, again, thank you SO much!  You are an asset to this great community.  I have my work cut out, but I'm looking forward to it.