Hook up your [pictslider] to send out some midi messages using [ctlout] using a different controller for the x and y output, then in logic select preferences > global > control surfaces > controller assignments > learn mode, then move whichever logic control you want to map to then in max move the controller (in this case either the x or y of the [pictslider]) that you want to map from and the midi mapping should be complete. You might want to use a number box rather than the [pictslider] to specificly send the x or the y value. This should work but I make no promises as I only dabble in logic 7.2 I hope it helps though.

lh