Can a mounted image be copied from 1 external hd to another ?

Gday

I have just mounted my backups to a 2TB external hd, can someone please tell me if I can copy these mounted images over to my 1TB external hd?

The reason being, I have 2 x Internal hd's which have all been partitioned off for a variety of reasons. The 2 Internal hd's go from C:\ throught to M:\, my 2 External hd's have taken the drive letters N:\ through to R:\.

D:\ and E:\ are my DVD Roms.

I have mounted my OS to the suggested Q:\ by acronis 2011, however I have also mounted all of my other partitions, and it has come down to a lack drive letters, as I have a barely used 1TB external (This is where I keep my windows backups), I was hoping to be able to either mount them onto the 1TB external, rather than on the 2TB external, where I have all my files backed up, and also the acronis backups.