STSADM migrateuser log file

I have a script to migrate 500 or so users from one domain to another in MOSS 2007 Standard. The batch file script works fine. I'm trying to locate or create a log file for the script that will tell me who has migrate successfully and who has not for one reason or another. I tried using the >> c:\log.txt at the end of my command line but it does not echo the user for instance:

stsadm -o migrateuser -oldlogin domainA\user -newlogin domainB\user -ignoresidhistory >> c:\mlog.txt
stsadm -o migrateuser -oldlogin domainA\user -newlogin domainB\user -ignoresidhistory >> c:\mlog.txt

Surely there must be a better way.

Thanks