Solder mask over footprint?

Trying to make a touch pad so I want the rectangular footprint to sit beneath the epoxy what steps do I need to take to not make this footprints copper visible (but silkscreen visible on top of board) ?

You could create, say, a footprint with 5mm rectangular pad. On the pad properties untick thie F.Mask layer on the right that appears by default when you choose an SMD pad type.

Without the soldermask you should see you copper pad covered

I’m a bit confused. What do you mean with rectangular footprint beneath epoxy?

Do you really want to have an inner layer exposed? (The epoxy milled away?)
I’m not sure there are manufacturers who could do this.

Maybe make a sketch that shows what you want to achieve.

I think he wanted to say soldermask instead of epoxy. I guess so because he mentioned a touchpad button (capacitive?)