easily,
open both plug ins (insert both soft synths)
on the soft synth preference menu screen that you are promt with directly after insert takes place be sure to select all outputs stereo and midi source.
its not that you need all outputs stereo but in order to configure your midi tracks to trigger the other they must be set this way.
go to ez keys track output drop down menu and select "Dimension pro"
you are essentially patching the synth.
not sure why one would want to take this approach but I can only guess its because of the record/edit features of ez keys.
im not here to judge but that's what the piano roll is for and 10XXX more flexible/powerful.