Oh, wow. I can't believe I didn't try that.
It works perfectly, thank you!
For future reference, here are the names of the powerups:
function x1001y1000()
Objects.Player.Run = 1
Objects.Player.Climb = 1
Objects.Player.HighJump = 1
Objects.Player.DoubleJump = 1
Objects.Player.Eye = 1
Objects.Player.Detector = 1
Objects.Player.Umbrella = 1
Objects.Player.Hologram = 1
end