How to change MyIE2 browser icons

[lynchknot]

I'm trying to change the toolbar icons in MyIE browser by changing the bmp images. I converted a png to bmp but lost the transparent background image so it left me with a square white background on the toolbar - other than that it worked. If you have knowledge of this please help as I am pretty much guessing as I go along. Here's a before and after side by side shot:

http://www.boomspeed.com/hotknot/beforeafter.JPG

and this is what i'm trying to achieve:

http://hotknot.netfirms.com/screenshots/toolz.JPG