Yes but you'll have to do it manually as the ifused field doesn't support zones.
So in the zone script init(e) function set
SetActivated(e,-1)
and in the main(e) check that value at the top
if g_Entity[e]['activated'] == -1 then
return
end
Then you can change the value from some other entity based on your conditions with
SetActivated(#,1)
(Where # is the entity number of the zone)