scook
FWIW, there is no need to physically copy anything, the DOS mklink command with the /d or /j switch is your friend.

Thanks for that.  In my C directory, I created a (/d (tried also with /j)) link for the toontrack Midi folder.  I then created a folder in the AD1 user MIDI directory (referred to above), using the link name, and it tests ok in Windows Explorer.  However, it doesn't appear in the AD Beats browser (after refresh).  Ditto when I try a Windows shortcut.  Sigh. 
 
Looking carefully, I see there's a folder called "GM" installed natively in the AD User Midi Files folder.  It too doesn't show up in the Beats browser. 
 
Understood I could probably make links on a file to file basis, but that'd be thousands .
 
Tx anyway,  -Ron

Using AD1 I was able to add the Toontrack MIDI files
Using the following
mklink /j "C:\Users\scook\My Documents\Addictive Drums\User Midi Files\ezd" "C:\Pr
ogram Files (x86)\Toontrack\EZDrummer\Midi"
 
Then opening Beats in AD1 and clicking "Refresh Library" added all the files.

scook
Using AD1 I was able to add the Toontrack MIDI files
Using the following
mklink /j "C:\Users\scook\My Documents\Addictive Drums\User Midi Files\ezd" "C:\Pr
ogram Files (x86)\Toontrack\EZDrummer\Midi"
 
Then opening Beats in AD1 and clicking "Refresh Library" added all the files.

Yesss!!  Thank you so much!  I completely misunderstood mklink.  I thought the "Link" parameter is just a symbolic name.  I see now it has to be a *path,* just like the target. As I think about it, that's a plain DOH!
 
Will worry about mapping later.
 
Thank you!!  -Ron

I use full path names in my mklink examples because they work regardless of current working directory. If the current working directory is C:\Users\scook\My Documents\Addictive Drums\User Midi Files the mklink command could be simplified to:
mklink /j ezd "C:\Program Files (x86)\Toontrack\EZDrummer\Midi"
 
Glad it worked for you.

scook
I use full path names in my mklink examples because they work regardless of current working directory. If the current working directory is C:\Users\scook\My Documents\Addictive Drums\User Midi Files the mklink command could be simplified to:
mklink /j ezd "C:\Program Files (x86)\Toontrack\EZDrummer\Midi"
 
Glad it worked for you.

Understood.  What I meant above is that I was creating a new directory in the AD....\User Midi Files directory, and giving it the name of the "link" parameter I had "created."   Note to future searchers:  Don't do that.
 
Thx again, -Ron