How to use LFO utility to modulate a VST in Reaper?

[R7T]

Hello, can someone help me figure out how to get CC from an LFO utility CV out from Reason Rack and able to modulate settings of a VST instr/fx? I figured it out at some point but I've forgotten unfortunately.

So far I've hooked up the LFO utility to the midi out instrument device (CV1 of CC in to MIDI CC out).
I have the rack plugin on the same instr/fx chain as the fx device so I go to the parameter modulate button on the fx's setting automation lane and choose the "link from midi or fx parameter" but I don't recall which CCs are linked to the CV inputs of the Midi out device to get modulation going. Maybe there's something else I'm missing. Thanks for any help.