If the RGBHV signal is a VGA signal than you can use the sync-combiner cable that comes with option VGA. If this is a normal component video signal that happens to have H and V sync broken out into two channels as some camera models do, you can simply combine the H and V sync back together into a single sync channel using a BNC T-connector. This combined signal can then be used as a normal sync signal with the VM5000.