23 in. computer monitor will definitely be most likely 1080p (1920 x 1080) or 720p (Some lower resolution, 1600 x 900, though this is less likely) depending on the model; there is no way you'd want to stick an RCA cable to it. Using S-Video will result in pixelation, graininess, and all-around terrible-ness.
What you should do is grab a DVI to HDMI cable and use that to attach to your monitor. As for audio, which won't transmit because the monitor doesn't accept audio, just grab an RCA to 3.5mm cable and hook it to your PC's line in. Or if you have an optical port, use that for audio.