help assigning the <ESC> key to a midi button press

[6xes]

Hi all,
this is my first post on the reaper forum

first off Reaper is great!!
having now entered the world of midi/audio daws etc, i purchased a few other midi controllers.. and see the benefit of working with them for both editing and musical input

my question is...

how do i assign a midi button to use the <esc> key or any key press for that matter
its funny
i have programmed a BCR2000 and BCF2000 for editing and FX manipulation but cannot figure this one out lol

any help would be much appreciated
thanks

[6xes]

i wish to use the function of <esc> key to close a window
or again,
use <cursor up/down> to move the highlighted cursor in a window
and again
Press <enter> to select or de-select a function

i cannot figure this out...

im aware there are specific function for actions... but using that method uses up more buttons than necessary...

im trying to economise on Midi-buttons being used for multi-selection