Dome light wiring question

I would like to add some additional interior lighting to my car, namely in the front footwells, but I only want them to come on when the dome and map lights are on (like door opened, dimmer turned all the way up to turn interior lights on, etc.) and not when the map lights are manually turned on.

Does anyone know which wire(s) I need to tap into to activate a relay for these extra lights?

couldnt you just tap into the power wire thats going up to the dome light?

couldnt you just tap into the power wire thats going up to the dome light?
Do you know which wire it is? I'm looking for something that's up front so I don't have to run wiring from the light, all the way back to the front of the car. I could do that, but figured it would be easier to know which wire in the dash is the wire that drives those lights.

Anyone?

I want to know too :)