I think Joe figured out why Mike's method worked... because it's not actually creating the file unless you use the browse button ("..." button). This may be the key to your problems if you're having trouble creating the oldsim.raw file.
"Definitely worked fantastic! I used it to unlock a MOT MPX200 from ATT
Wireless to T-Mobile--took a little while to get it to work and one thing
was messed up. When you save the oldsim.raw you have to choose where it's
going from the box with the "..." so that way it actually makes the
progress of creating the file, I just chose to put it as c:\oldsim.raw and
it didn't work until I used the "..." button.
But it was awesome. Leaving credit where credit is due.
Thanks for the tip on using the browse button to create the oldsim.raw file, however I have a different issue. After creating the oldsim.raw file (on two different machines) in command prompt I get the error :
"cannot read input file :c:\oldsim.raw" therefore I am unable to create the newsim.raw file. Any ideas or suggestions?