@larryg -
you're absolutely right about the problem not being easy to resolve. in addition to the directory paths in the preferences of sonar that you need to change (there are 15 that you need to worry about from project files to fx chain presets) there are also registry entries that deal with paths in the media browser and things like prochannel implementation. when you move directories and open sonar, all the file paths are reset and it's a real big pain in the a$$ trying to set everything up again. first time i made that mistake it took about 3 hours to put all the pieces back together.
that being said, what i do now is known as symbolic linking and i'll give you a place to start.
say your external drive has the letter f:
open windows explorer and select "cakewalk content" and "cakewalk projects folders" and MOVE THEM to drive f.
then, open a command prompt and type "cd c:\" to get to the root of your boot drive (assuming that's where the folders in question were.
then, make symbolic links to the new file locations by typing the following:
mklink /d "cakewalk content" "f:\cakewalk content" ===hit enter===
mklink /d "cakewalk projects" "f:\cakewalk projects" ===hit enter===
this essentially tricks windows into seeing the files in the original location even though they have been moved.
just never start sonar without your external drive plugged in though. could be nasty.
hth