[edit] WickedX ninja posted...
You can use
save image. If you have the bitmap, convert it to an image and save it like this:
set current bitmap BMP
get image 1 , 0 , 0 , bitmap width(BMP) , bitmap height(BMP)
save image "filename.png" , 1
I remember there being some problem with the saved image scaling itself to a dimension with the base of 2 (like 128x128, 256x256 etc. but nothing in-between, even if your bitmap was something like 5345x823). There's some flag you need to set and I don't know what or where

Could someone post a solution to that?
TheComet