I am changing the appearance of an Add-in Toolbar but I was able to use .bmp files as icons.
The problem is that .bmp images are of very poor quality and all of them are kind of blurred while the same images as .ico or .png look very nice and sharp.
By now I am using LoadFace method that does not allow to use .ico and .png.
I hope it'd be possible!
Thanks in advance.