I can offer you a partial solution. This code will map a drive if it
can. The error portion of the code you can attempt a different drive,
or whatever.
Sub Map()
On Error GoTo MapError
Set Map = CreateObject("WScript.Network")
Map.MapNetworkDrive "F:", "\\server\folder", , "UserName", "Password"
Set Map = Nothing
MapError:
MsgBox ("F is connected already")
End Sub
I'm not sure how to verify password/username accuracy.