Here's a great bitmap editor written in Assembler
It has plug-ins to save as icons and other features
that you can read about here:

Also, don't forget that Irfanview has the ability
to save your bitmaps as icons using your context
menu in Windows Explorer. It will even ask if there
is a color you'd like to be transparent before it saves.

Michael R. Mattys
Try MattysMapLib for MapPoint at