exec/external.bat does not work with dosemu2

environment variables used for lredir with \ (DOS backslash) fail on dosemu2

E:\freedos.com>lredir -n linux\fs\sbbs\doors\dos
Error b (format invalid) while redirecting drive K: to \\linux\fs\sbbs\doors\dos

should use / (linux slash):

E:\freedos.com>lredir -n linux\fs/sbbs/doors/dos
K: = \\linux\fs/sbbs/doors/dos attrib = READ/WRITE    

So all environment variables used in exec/external.bat need to be changed from '' to '/' for lredir to work properly maybe through ctrl/sbbs.ini it is tried to add an option UseDOSEmuVersion=x where x can be 1 or 2 (1 as default) and use this option as dosemu quirk. thanks!