[racket] How to create a new DrRacket keybinding that also repositions cursor?

Dear list members,

I want to create a  DrRacket keybinding that will produce   #||#
but will also reposition the cursor position  between the two upright
bars. i.e. #|<cursor-here>|# .

Can someone show me how to do this.

Thanks in advance,
Harry Spier