Not the whole song, but I have figured out the intro of the song. It is a short song so I should be able to knock down the rest some time soon or someone can take it from where I leave off.
I played along the original song, not the one covered in Main Hoo Na, and it sounded close to me. I will let you all be the judge.
(Am)Chaand mera (Dm)dil,
(G)Chaandni ho (C)tum,
(C)Chaand se hai (F)dour,