In this day in age everything has wizards, this also being true for creating a new scheduled job on a server.
Now I did not research this in great detail, so bare with me if I overlooked something, but I had problems omitting an account and password when creating a new scheduled job. I wanted to create a schedule witch would run under the systems account, and let me tell you it got old REALLY fast, damn wizard would not let me create the job.
So back to the good old dos AT command I think, but wait I thought was there not an old utility in NT4 that had some kind of GUI.. Google->Search->Found 
ftp://ftp.microsoft.com/ResKit/nt4/x86/winat/winat.exe
So if you like me experience problems with those damn modern wizards, download this and be happy (its even a bit nostalgic to work with an NT4 util again :-))..