So, I finally got around at trying this. So far, it doesn't yet work exactly as it should. Some basic things already work quite well, though:
My compiled autohotkey-script "NecroMount2.exe" gets started automatically as additional app with the game from launchbox and can be seen running in my taskbar while the game is active and I change to Windows screen.
It ceases to be active after executing MOUNTCD2BAT, as expected. Pressing "*" starts the MOUNTCDBAT.lnk command, as wished. MOUNTCDBAT.lnk can be started minimized and generally changes CD1 to CD2 when I start it from desktop.
Right now, I can't execute it when the game is active as the MOUNTCD2BAT gives me "close running instances of virtual drives" errors. But I think this should cease when I'm at a point in the game when it wants me to swap isos. I'm not quite there, yet, though.
BUT, right now pressing the "*" key only works if I get out of the game screen to the desktop. As long as I'm in game environment, "*" gets ignored. This way, setting the hotkey isn't that much easier, if I have to alt-tab myself out of the game, it would be just as easy to start the old additional app from launchbox and alt-tab my way back. Hmm, is there a modification of the AHK-scrip possible that makes the hotkey active with the game screen running as active surface?
When I think about it, for these old WIndows games cases, setting up several hotkeys for each iso could be useful, AFAIR there is also "EVIL DEAD - HAIL TO THE KING" that needs to be run from isos (i.e. doesn't have a complete harddisk install option). I think you had to change to CD2 and again back to CD1 later in the game. So it would be even better if AHK stays active as long as the game is running and gets setup with two action keys, say "*" for Disk 2 and "-" (Keypad) for re-changing to Disk 1.