http://i.imgur.com/TzFR5EG.png

only ones you can use are those and they're controlled by engine

Think he means something like this but prob for guns or something, but works the same, using menu

! No longer available

Yeah, this is the thing I meant. Only want it to show with one trigger, so yeah. In what menufile should I be adding the itemDef then? And what kind of itemDef would it be?

itemDef
		{
			name			"hintstringicon"
			rect			15 15 30 30
			forecolor		1 1 1 1
			ownerdraw		CG_PLAYER_WEAPON_BACKGROUND
			exp material		 (dvarstring("myhintstringicon"));
			visible	when ( dvarstring("myhintstringicon") != "");
			decoration
		}

Triggers are only relevant to your method. I made a different hintstring method for the perks using a dvar to set the hintstrings in menu. Then to add the icon, it was just a matter of adding another itemdef to that looking for another dvar. This can be set in gsc.

For example, here is trems hintstring fix, that is done this way, without the added image of course:
http://ugx-mods.com/wiki/index.php?title=Hintstrings_not_updating

The itemdef to add could be like this:

itemDef
		{
			name			"hintstringicon"
			rect			15 15 30 30
			forecolor		1 1 1 1
			ownerdraw		CG_PLAYER_WEAPON_BACKGROUND
			exp material		 (dvarstring("myhintstringicon"));
			visible	when ( dvarstring("myhintstringicon") != "");
			decoration
		}

Then you would edit the gsc so it set that dvar to "" or the shader you want to see at the time. How you do that is up to you, I use a multidimensional array and pass a var to get everything I need. But for his, you could prob just add another var to the sethintstring function, then check ifdefined set the dvar to that var, which would be the name of the material, but if it isn't defined, to set it to "". And where he sets all the dvars to " " or 0 in sethinstring_show, you would set your new dvar to "". That should work. You may have to adjust your rect though.

There may be an easier way, I haven't tried, cause I already had a system for hintstrings in menu, so I just updated that.