the system code should be listed in the document the vendor provided to you.  this will stay the same for each code you are generating.
the command field will differ for each function.

bascially, you right click the empty box, select new code, then select the type of code (rc5, rc5x, or nec)

then you enter the system code and command code

then click ok and you will end up with a hex string

then right click anywhere in the box and select "convert to raw"

now you will have a full pronto hex command that can be copied and pasted into whatever program you are using.

if you like, you can email me the document and I can generate a few for you to show you how.   my email is in my profile.