For a time I had this exact setup. You don’t need an external clock controller. I did it via MIDI.
I used a UR-22 on the Cubase laptop and a simple little MidiMan MIDI interface on the Resolume one, and connected output of Cubase MIDI to input of Resolume MIDI.
Resolume has options a pretty rich variety of MIDI triggers. I wrote a MIDI track in Cubase and that’s where I initiated the events that would happen in Resolume. I believe I used, in my case, MIDI notes in Cubase and then in Resolume set events to trigger on a given MIDI note.
I wish I could give you better step by step instructions I no longer have this setup running. Hopefully this will get you in the ballpark, though. If you look into MIDI event triggers in Resolume and get comfortable with that, then it’s just a matter of creating a MIDI track in Cubase to make Resolume do what you want.
It’s a really fun setup with a ton of flexibility. If I can help further just let me know and I’ll do my best.