pcx files

I am currently using the latest version of gimp, and stuck on figuring out how to copy one scenario's building large pcx into another large pcx essentially combing the two. I also see I have to change the index ID so two buildings don't share the same directory once merged together. Quite a...

Hi, I am wondering if someone can help me. Hopefully this is in the right place. I want to add more units to a mod, and used GIMP to open the pcx unit file, but after saving and then reopening the file, it is all distorted. Which program is best to use? Thank you.