Ok I dropped the \ from mine and it did work so corrected above. It didn't with the .dl_ because it errors out and don't expand.
Are you saying it will set the keys itself now? with the Register option
? Errors out ? What kind of error ?
And yes, basicly thats what the Shell Extension menu does, though its a slightly different approach, i dont use (overwrite) the edit\command Regvalue, instead i add a "WinntbbuED" entry to the context menu, this is a bit more friendly for anyone who already has associated dll's edit\command to something else like e.g. a HexEditor
But it's based on your suggestion, btw did you check the about lately?