trigger adobe form in update task

Hi,

I need to attach a billing doc o/p to shipment while its being printed using Adobe form. Right now setting GETPDF = 'X' is working, but stops the print preview or the actual .print. Instead thinking of calling the same form in update task so that this time we call the form with GETPDF = 'X' and then attach this. Do you think this is a feasible solution as FP_JOB_OPEN and FP_JOB_CLOSE in update task ? Or do you have any other alternative ?