Alraedy requested this long time ago, never heard from it again but several new winbox version passed now without such possiblity:
Option to have several versions of Winbox loader side by side in Windows (or Linux?).
In stead of having the need to fill all my IP's in one loader version (or get them from any other source and fill them manually) it would be nice to have several different version of winbox side by side.
I could then for instance have a winbox loader with only my AP's or routers in. And another with clients (CPE's) Or when the network becomes really big, I can make several loader versions, each for each IP network.