So you want to go from component video to composite video? Most newer AV recievers can handle making this switch. You can also buy some switch boxes, down coverter, or scalers. But keep in mind that component is meant to be analog HD. Composite (single yellow) is old school for video.
They make Component to dvi/vga/hdmi/s-video (pick whatever end you want) cables. Just search google. What are you trying to connect together? Something to your RCA switch that goes to the TV.
Well my PSP and my DVD Player are both Component, my switch (4 devices all routed though the same device so i can change the devices with the push of one button) is also Component (but it also has a single Composite outlet as well so i can do either)
But our TV is only composite (and coax) I need to find a way to get them all to play nice with my tv because right now i can run some of the devices via composite in and out but if they only have Component out (like my PSP) then the TV stays dark.