Depending on the specifics,  you might be able to do it without a script,  just the basics of the custom office.

For example,  you can have a UDF on a sales order automatically transfer to the created sales order invoice by specifying the source when you create the UDF in invoice (look at the options for source for UDF data).

Not sure how that helps me with a UDF in the Item maintenance cost detail table.  Please elaborate.  I am looknig to use a script to give me a user input dialog box to add data to a udf in the cost detail table where it lists all of the lot#s with their respective on hands, costs, etc.

I've done this with and a Custom Office dialog box for message and input plus scripting. One issue I had was being able to refresh the Item Cost tab in Item Maintenance immediately to match the dialog box which required a manual refresh.

sounds great.  would you mind sharing your script?  that is the part i haven't been able to figure out.  how to make it write to the given lot# on the table

Due to a bug in MAS where one cannot Open a dialog box from an advanced script (anyone know if that's fixed?) there are actually 3 scripts and 3 buttons that invoke them. Way too complicated layout all the scripts and connections between buttons, but basically I have:

1. One button on the Cost Detail panel that saves the Lot/Serial data in to UDF's then runs a user button script

2. This 2nd button script launches the dialog box (that can't happen on the server side because it uses SendKeys to invoke the dialog box)

3. Another button script attached to a dialog box button that writes the UDF's  to the ItemCost table