First you have to give us an example of your toolbar file, so we can see if you have made some error. Though i can give you an example from mine (I use xterm):
prog "XTerm" "xterm" xterm
In my case i use IceWm's built in icons, so it is enough to write "xterm" in the icon-field. Every prog row in the toolbar file has 3 options, in order: Name (Call it what you want), icon file (png or xpm file), command to execute the program in question (with options if you want).