xcopy [source] [destination] [switches]

If it's scripted with perl, do a localtime command, extract a satisfactory string, and build the dir to use as destination:

($sec,$min,$hour,$mday,$mon,$year,$wday,$yday,$isdst) = localtime(time);
$months++; # January being month 0
$loc = qq¦E:\Backup\bu_$mon-$mday-$year\¦;

Hmm in retrospect you may have to execute mkdir to create the dir first . . .