Transform fast changing incoming parameter into smooth ramp up (or down).

Hi there,

I have a question that might sound a bit dumb, but I'm looking for an object, equation or algorithm that will allow me to "slow down" and smooth a fast changing parameter. The idea is transforming an incoming MIDI CC that rapidly changes (lets say from 0 to 127) into a smooth ramp. The object (or algorithm) should also "catch up" with incoming changes, meaning that if the incoming parameter changes before the ramp reaches the maximum (or minimum) value, the output will "catch up" with the input. The idea is getting on the output some sort of "slo-mo", inertia-affected version of the input. Any ideas?
Any help will be greatly appreciated. Thanks so much in advance!

Best,

Martin