Can't promise you can "force" these plugins to do what you want but they're in the ballpark. If it can be done with a plugin MIDI FX VST is the place to look. Ableton has some in built MIDI tolls for velocity and scale stuff that might work to. The trick would be how definable the parameters are, hopefully extensive enough for you to do say 16 ascending values through the plugin and what not.
these were the two that looked in the neighborhood.
"midiSwing - Delays and/or offsets velocity of and applies probability to notes (and optionally also CCs) at every other step of a selected note value.
midiVelocityScaler - Scale/reverse/offset velocity of input notes (Note On and/or Note Off)."
http://freemusicsoftware.org/category/f ... ent-filterLikely PC only I don't have these installed though.