I SO know what you're going through, I almost lost my nails during french. I doubt you'll use them all but here they are. I'm not sure if this is all, but it's what I found.
à- option, `, a
î- option, i, i
â- option, i, a
ï- option, u, i
ç- option, c
ô- option, i, o
è- option, `, e
ù- option, `, u
é- option, e
û- option, i, u
ë- option, u, e