Hi,
Ah, that means the issue is not really about this particular BAPI, but a general inexperience with ABAP. You didn't make that fact clear.
That's why our responses weren't much use to you - we assumed some basic knowledge.
I think you should start with building and calling simple function modules in ABAP before you can graduate to handling complicated BAPIs. It's not too hard - a bit of persistence is all you need.
good luck
Paul