[Brian]

Sorry for the confusion! According to the Keyboard Viewer (available from the Keyboard pane of System Preferences) it looks like Option-C and Control-Option-C are both meant to produce this character: "ç".

However, when I press the latter combination of keys in Safari, Mail, TextEdit, or OmniFocus, no new character actually appears in the text areas. The Mac accepts the keypress, but no character comes out the other end. (This is on a Mac running Lion.)

I'm not an engineer, so I don't really know why that's happening, but it would explain why the Command-ç shortcut isn't working for you. Unfortunately, just dropping Control isn't really going to work - too many apps use Command-Option-C for "Copy Style".

Really sorry, but I think choosing a different shortcut is going to be the easiest workaround here.