Three things. (and why i down-voted your post):
I have the code to do this using gluUnproject, but apparently, im too noob to help so, too bad...
1. You can't actually delete your posts, their's this handy thing called history, and everything you've done/said is still quite accesible.
2. Getting angry about being down-voted is completely immature, accept it, and move on. You yourself escalated the situation when all people did was give you reasons not to use macros, and everyone was very polite about it.
3. Taking out your frustration to other threads is even more immature.
So your options are to either leave gamedev because you can't handle the community, or to learn to accept criticism when someone disagrees with how you do things. Noone is attacking you directly, they are simply saying their are better ways to do something.