In your mt.cfg, you should see a section that says this:
QUOTE
# By default, the script that Movable Type uses for comments is called
# mt-comments.cgi, the TrackBack script is called mt-tb.cgi, the
# search engine script is called mt-search.cgi, the XML-RPC server
# script is called mt-xmlrpc.cgi, and the dynamic blog view script is
# called F. In
# some situations--for example, if you are running MT under mod_perl, or if
# your server requires that your Perl scripts have the extension .pl--you
# may need different names for these scripts. You can set the names that will
# be used throughout the default templates and Movable Type code by changing
# these values.
Try changing
# AdminScript mt.pl
to
AdminScript XYZ.CGI
Make sure to remove the # a the beginning of the line.
Kymberlie