Thank you for your help. That worked like a charm!

Help - I am too stupid! I want to disable a few functions that are used in DOSbox, because I want to use them in the program I am running with DOSbox. For instance I would like to use Ctr-F4, Ctr-F5 etc. I can't figure out how to do that with the keymapper. Or is there another way to do it?