Spare Remote for Denon D-M39DAB?

[Morpheus]

I want to get a spare remote control for a Denon D-M39DAB micro-system.

I only need it to control the amplifier's volume from across the room - the other functions are superfluous.

Can I buy one of those "universal remote controls" for a few pounds? Do they really work with anything?

If not, what's the best option?

TIA!