multi npcs on 1 sprite

I have one sprite instance and have 12 npcs with their different walking animations for each direction.

boy1left

boy1right

boy1up

boy1down

boy2left

boy2right

boy2up

boy2down

How do i get it to play the correct direction with the correct boy?, i need the expression to say "whatever boy is playing and the direction".

set animation to "boy1" & "up" (the "up" part is determined by a value)

The above code works with fine with one npc per different object sprite but im trying to combine them all in one sprite. Can this be done?

Instead of using a static value to represent each and every action, use instance variables to represent which version to display.

I am assuming the list above of boy number and direction is what you name each of your animations.

Use a variable to store the selected boy number: BoyNum = 1

Use a variable to store the selected direction: BoyDir = "up"

Then when setting the animation set it to: "boy" & BoyNum & BoyDir

The above will result in the "boy1up" animation being played.