Custom Item Icons under the W3M editor

Im using the enhanced world editor, im not quite sure what its called but its the one that comes with the W3M map utilities program. Anyway my question, im making some custom item right, and the items model is: ReplaceableTextures\CommandButtons\BTNOrbOfFire.blp
Ive seen some maps where items look like armour/attack upgrades and some other stuff like that (defence of the ancients etc). How do you find out the link for the pictures; like for example i wanted to make an item called shield; and have the graphic as the first human armour upgrade. How would i go about this? emote_confused
Btw is this in the right forum?

Get UMSWE. With it comes a list of all icons. Or you can use something like Image Extractor or War3Explorer, where you can also view the icons. Anyway, with WinMPQ, which is, I think, a part of the Map utilities you can open war3.mpq, which contains all data. Set the file filter to *.blp and look at all files with BTN in ther name.