Super VGA to 1 BNC monitor cable

I have an old SuperMac STD9761AV (Platinum 21 Two-Page GS) monitor. I found the following info on the internet:
IMPUT SYGNAL
Video Signal: analog
H Frequency: 60.34/68.68 Khz
V Frequency: 75Hz
Sync Signal: green
VIDEO BANDWIDTH: 80Mhz
INPUT CONNECTOR: 1BNC
MAXIMUM RESOLUTION:
1152×870; 1024×768
I have a Matrox Millenium G200 video card and I would like to use that monitor too.
I bought: 1 bnc connector, 1 VGA connector (15pins) and a coaxial cable. How shall I connect those two connectors? The info says that the sync signal is the green, shall I connect the green pin to the middle pin on the bnc? And what is the pin for the green on my video card? Any suggestion would be really appreciated. Thank you in advice.
Xanthor