Strange modifier request

[sirann]

Good (insert time of day you are reading this in relationship to the sun),

I have a rather strange request so I'll give some background as to why, and hopefully that will also better explain what I'm looking for. I am an active raid leader and am quite vocal, the downside being I frequently have to call things out via a push to talk button over vent (left alt is this button.) All of my macros are set up in a pretty similar format as follows:

#showtooltip
/cast [nomod][mod:alt] x
/cast [mod:shift] y
/cast [mod:ctrl] z

this allows me to free up action bar space and use the free action bars as non addon requiring cooldown bars (yay less cpu/mem!)

What I'm looking for is a way to write the macro as follows:

when I hold either no modifier or my vent button (alt) it casts ability x, when I hold either the shift modifier OR (shift AND alt) modifier it casts y, and when I hold either ctrl or (ctrl AND alt) it casts z.

there are a few rare instances that I have to release my push to talk key to hit a keybind that is either a shift or ctrl modified key, and thus can be rather annoying.

I appreciate your time.