BPM to check for character entered

I am pretty new to BPMs. I am trying to figure out a way to have the BPM pick up a Job Number, Assembly, and Operation being scanned in and fill the fields accordingly. I am thinking that if I have the barcode start with a certain character, that character will trigger the BPM to allocate the rest of the barcode.

What module are you doing this on? This sounds more like a screen customization than a BPM. (Right tool for the right job)

I actually spent most of today trying to figure out how to do it with a customization. I posted a question on here earlier about that: Adding hotkey to MES

What screen are you doing this for?

I am working in the Start Production Activity screen.