Okay. So, I think you have two options...
1) Replace the cable with one that has the NMEA-2000 connection that you want on the end, such as by cutting off one end of a cable and wiring it into the terminal blocks, as earlier described
2) Using the male-male SimNet connector AND the SimNet to NMEA-2000 cable earlier show, or similar, to adapt what you've got to what you want.
I don't think it super likely you'll find a cable with a male SimNet connector on it that goes to NMEA-2000, but, you can find cables like those shown in my earlier email in various lengths.
If it were me, I'd replace the existing cable with the one I wanted of the length I wanted and save the adapters. It is cheaper and has fewer parts. But, I totally understand wanting to leave well enough alone and just adapt.