synnths

Hi, So i've been playing around with the Creation kit as well as Nifskope and made a few weapons using custom meshes (such as an ACE 21 CQB, Mp443 grach.. etc) And of course aiming down the sights doesn't work all that well, since the Iron Sights have different heights from that of the vanilla iron sights. Im sure its possible, but i wasn't able to figure out how, and where to make the iron sights for custom weapons so they align like they should. Could anyone please help me with this little problem, and give me some info on how i could do that?