Region Definitions?

[HiRaX]

Ok, so say I'm editing 2 pieces of music both exactly the same only one is an alternate mix with say the lead or main melody muted.(Like a bed) I'm making different length edits of one mix and would like to have the exact same edits on the other mix in a different session.
How do I go about doing this? Do both mixes have to be in the same sesison?
Do I use Export Region definitions? I'm not sure how this works, but if anyone could shed some light on it I would greatly appreciate it.

Thanks

[minister]

why not put them both in the same session and group the tracks?

or is this already done?

if it is, then maybe copy the session to another drive, copy the bed version of the music to that drive, and name it the same. maybe remove the old drive from the system. open the copied session on the new drive and relink the regions to that drive and file.....

[HiRaX]

Grouping sounds like a very doable idea, thanks.
I have tryed the renaming thing and that didn't seem to work.