Making wired speaker controller wireless

So I have a set of surround sound speakers that only has one of those wired controllers for the power and volume. I was thinking about buying a new set that worked with an remote control, but then I realized that I might be able to hack my current ones to work. I could get a simple IR receiver to hook up as a digital input, and replace the power button with a digital output. And replace the volume knob with either a PWM output. Does this seem sensible/feasible? I've had a fair amount of experience working with electronics, i just wanted to see if this made sense before going out and trying to crack my speakers open. Thanks

So I thought about it more, and and the on/off button should be easy to do. I guess the 2 big questions are:

-Is a volume knob generally just a potentiometer that could be replaced by pulse-width modulation?
-Can the arduino work with an IR sensor? I saw a guide of someone mentioning that they used one, but would you be able to program an arduino to accept commands from a typical universal IR remote?

I'm sure this isn't a common project, but any input or advice would be greatly appreciated

Regarding the IR remote se this famous blog:

-Is a volume knob generally just a potentiometer that could be replaced by pulse-width modulation?

Volume control could be a pot (cheap 2.1 system) or rotary encoder. If your controller doesn't have remote, likely it's in first category, and things are little bit complicated, as it 'd require digital pot or led-photoresistor substitute.

Thanks Erni, thats perfect. Thank you also Magician. I was thinking that if a potentiometer is just a variable resistor, the system would read the volume off of it by seeing what the voltage across a second resistor in series is. I was hoping this could be emulated using PWM, but it sounds like it can't. I'll look into digital potentiometers a little more then