Drag gui text and drop it on 3d object.

So you heve a / mouse down -/ mouse up \ for inputs and just a Raycast from pointA(guiText) to pointB(Object);

So thats it :

 if(..Click and hold GUITExt)
 {
     if(..$$anonymous$$ouseReleasedWhileHoldingGText)
     {
         if(raycast....HIT)
         {
              if(compareNamesOrTags)//run Code
         }
     }
 }

I want to steer you in a positive direction rather than just spoon feed some lines. Ill help you if you need help, chops dont grow that way unfortunately..