Not URL:
try in your hard disk at:
WinSPMBT\Game Data\Graphics\SHPed.exe
Or whereever you installed the game.
This is Fred Chlanda's marvellous SHP edit tool!
Does everything from extracting icons as bitmaps, inserting bitmaps, checking position headers, preventing flashing colors...
IIRC infantry squads hang around from icon0010.shp to icon.0014.
Ask again for any help!
Oh, BTW, all this icon business aparently belongs into the oob mod subforum.
Cheers,
Plasma