Wouldn't that cause problems with other apps? Here's the menu file on accelerators.
***ACCELERATORS
// Bring up hyperlink dialog
ID_Hyperlink [CONTROL+"K"]
// Toggle Orthomode
[CONTROL+"L"]^O
Try changing:
pCONTROL+"L"]^O to
[CONTROL+ALT+TAB]^O
You might also try:
[CONTROL+SHIFT+"A"]^O
That would at least put you in the vicinity.