RadoX ... use photoshop. first this you should do is have each one of those icons in a layer separate from the background. then color the entire background black. then in channels pane add a new one. this will be the alpha chanel. then select your icons by ctrl-clicking on their image in layers pane. with the icons selected go to the new channel you created and press Ctrl-Delete this will create a white hole the shape of your icons on the alpha channel. then just save it as bmp and you're set.
heres a sample:
toolbar.rar