This script will apply user-entered text to the "Category" tag of each of the selected tracks. iTunes 5 or better.
(Note: In order to launch this PowerPC-era script on an Intel machine, it must first be opened and then saved using AppleScript Editor, which is located in your /Applications/Utilities/ folder. More information is here.)
Create a text file containing an alphabetical list of chosen tag data
Two scripts copy text from the clipboard to current or to selected track's lyrics
Convert selected tracks and export the converted files to a new folder
Play the selected track and stop
App displays files in iTunes Media folder which are not in iTunes library
Add or subtract a user-entered number from each selected track's Plays