Trouble formatting my resource string in general

Dear all,

After using AE for ten years and writing some script for other purposes than AE I decided to finally get into scripting for AE (CC) to make my life and the lifes of my co-workers more easy. Using David Torno's tutorials and Peter Kahrel's ScriptUI pdf I created some pretty useful dockable panels which import regular used templates, shapes, render-settings, watchfolders et cetera, using dropdownmenu's, buttons and checkboxes. Works smooth and let's us work far more efficient and consistent then before.

All acomplished using resource strings as seen in David Torno's Episode 12.

But now! The more functionality I want to add to my panels, the more I stumble across the problem were I don't now how to translate 'regular' script to a resource string and I just don't know if going the resource string-path is the right one. For example, in regular code I know how to add a custom iconbutton:

var importIt = myButtonGroup.add("iconbutton", undefined, myIcon, {style: "toolbutton"});

..where myIcon is a var with a long string which creates the image. This works as expected.

However, in my resource string I really don't know how to format the string. Where do I put the string to the image?

myIcon: IconButton{style: 'toolbutton'},\

I think my real question is, where can I find the various properties or format for the resource string? Do I miss something obvious?

Really stuck here, hence my first post, and hope someone can give me a push in the right direction. Many thanks in advance.