I'm not sure I understand what you're doing in that case. I thought you were renaming the files so that they were in track order, and then wanted to adjust the track number tags to match, but maybe not.
If you want to do it the other way around -- rename the files to take the track number from the music tags and put it into the filename -- then you can use {mp3track|#2} (assuming you want a two-digit track number, like "01") with the file information checkbox turned on. There are examples of that in the Various simple rename presets thread.