If you want a momentary switch that is triggered electronically, you can use an XOR gate or an XNOR gate for a momentary normally on switch or a momentary normally off switch respectively. If you want them to switch simultaneously, just link them to the same trigger (see file). If you want a toggle switch with an electronic trigger, use a T-latch (see pic.). If you want to turn a normally closed electro-mechanical pushbutton into a normally open one, I guess you could throw a NOT gate in series with it...