[classic] Bindings do not work with mod key - or am I doing it wrong?

[Dwargh]

I have a bar with standard key bindings 1-0 (+ 2 more buttons) First I tried macro [mod:shift] to alter spells on same key, but it wouldn't cast. So I tried making the bar with shift state. The bar shifts so that part works but pressing the bound keys does nothing. I thought perhaps the key is bound to only the non modded state, so I tries binding the shift state button to shift +key which still didn't help.

I'm lost for how to be able to use shift state buttons on key press.