Understood, opposit side from what I said. Between those pulleys is minimal gap, millimeter or so.

Well, nice try.

One other possibility is to put another pulley in front of the water pump pulley and use a second belt to drive the s/c. The original belt (shorter) can now be used as it is unnecessary to go over the s/c pulley.

Can these pics help to better explain where should be extra pulley fitted?
http://www.foto.rtd-universal.ru/n/images/IMG_0202.jpg
http://www.foto.rtd-universal.ru/n/images/IMG_0203.jpg

Try to draw the second pulley in front of larger one.

http://www.aquamist.co.uk/forum/pulley.JPG

You will also need to put another pulley in front of the supercharger or move the s/c forward. In most cases, you should be able to obtain a longer s/c nose.

Good idea, didn't tought that way at all.