Enter a new ItemCode, get the prompt, click Yes (...Item Maintenance opens) then fill in the required fields to create the item, Accept, then back to SO Entry...  No script required.

What functionality are you trying to add / change?

Hi Kevin, 

Thanks for the response. The user doesn't know the item code. The code is generated by the script.

And I would like to avoid that the user has to copy and paste it from a message box.

Sage has a feature to allow entry of "special" items which don't exist in Sage, prefixed by a "*"... so you could have the user type *NEW as the item code (and tab out of the field), then fire your script column pre-validate on ItemCode to run your logic when the value is *NEW...

That is a great workaround! Thanks for the suggestion. 

It worked. I had to write the ItemCode through InvokeChange.

		MASUI = CBool(oScript.UIObj)
		If (MASUI) Then
			Set myUIObj = oSession.AsObject(oScript.UIObj)
			retVal =  myUIObj.InvokeChange("ItemCode$", sNextFull, "GD_Lines")
			Set myUIObj = Nothing
		End If

It almost worked with InvokeChange. The only problem now is that after the item info has been entered in the Item Maintenance UI, it doesn't bring all the information into the line item. E.g. the ItemCodeDesc doesn't populate on the line item

I ended up using a workaround. I added a checkbox UDF to the line. The script now triggers when the checkbox is set to 'Y'. It writes the new item code to the ItemCode fields. The Sage logic takes over, and all information gets written back to the line as expected.