Project Accounting Re-Printing

So, I have written a Dex App that allows users to re-print Sales Order Transactions given a particular range.

My next task is to Re-Print Project Accounting Billing Documents using pretty much a filter.

I am having issues with the printing of PA. There is a script PA_Inv_Frmt_Process that I am using however, 

I've created the Sanscript code to execute across the PA execute (258, code, compilerr) but nothing seems to be happening, no error, just nada. I then proceeded to attempt to update the PA table buffer, but, can't do this via call with name command.

The next step was to attempt to use the native PA Entry Print window on the PA Billing Inquiry Zoom, but got issue there.

Any suggestion would be appreciated.

Thanks

David