Sadly I have not OFP installed anymore, but just looking at the code I may say very nice small script.
You might consider inscreasing the size of the script header a bit, as most people just copy the script in the mission and then forget forever about the readme, so you may add there the part that is missing which is the readme in English.
That script should be also fully compatible with ArmA just changing:
_NN = call format["%1Nombre",_Pista]
by
_NN = call compile format["%1Nombre",_Pista]
So you might consider to release both versions.