Cannot save a copy and paste in the killmark files PLEASE HELP

When I want to edit my kill marks I want to copy and paste some pictures into the original .TGA kill mark file.
But it wont let me save normally, if I do that, Can some one help me plz?
Also if I just make a new project and save it on my desk top it still wont be a .TGA file and wont work
Im new to PS cs6 so I dont know much but i would appreciate it if anyone can tell me what im doing wrong.

Thanks

No.
But i dont think you understand me.
You know how if you were just to edit the color of the mark folder, and you would save and it automaticly saves where it should.
Well if I dont just change color, like if I were to put in a picture by pasting. Then I would not be able to save normally like that.