WoWInterface - Targetting by clicking on frame

I have this frame that inherits SecureUnitButtonTemplate (it inherits a template that inherits SecureUnitButtonTemplate actually, but i guess it's the same) and i want it to target a certain unit.

When this frame loads it does:

Code:

this:SetAttribute("type1", "macro")

this:SetAttribute("macrotext", "/targetexact nil")

When clicking on it, it does: (i previously saved the target name in targ)

Code:

this:SetAttribute("macrotext", "/targetexact "..targ)

it doesnt work at all.

how to fix it?