Press buttons on a dialog

[Eoeo]

I made a dialog with some buttons ( btnbmp ) and I associated for each button an action

aBtn[nbotone]:bAction := {|oBtnOmb| my_function(oBtn) }
this when lMultiple is Off := .f.

when lMultiple is .t. I wish no execute the action and when I press a button it must be pressed with the border colorized (sample black)

then the final user make an order and the procudure must insert on array all numbers of the buttons pressed

for sample :

I press first . two, and third button then open a dialog and the procedure let me return the numbers of the buttons pressed

How I can make it ?