How do you change backgrounds using PSP 7?

[Exsanguination]

My wish: to change the invisible background fo the military advisor to an office-looking background so I may use him as a non-animated leader head.

Using PSP 7 (Photo Shop Pro), is this possible? If so, how????

 

[Bjorn Bjornson]

i dont see why you couldnt, just as long as the background graphics match civ3 pallettes