how do i convert or emulate Wonderswan Color rom to Super Nintendo Entertainment System?

what? no. you can't convert one systems roms to another. you'll have to use a wonderswan emulator for those games.

well i heard there is some emulator that can play wsc roms as though an snes rom or something like that

You need to be a little more descriptive than that. Sure, there are emulator for various consoles, but I have never heard of a WonderSwan emulator for the SNES (let alone the fact that it's more or less impossible to play emulators on cart-based system anyway - unless you want to start reprogramming and soldering ROM chips to spare carts). The SNES itself is too weak for emulation anyway.

The SNES does however support the original Super Gameboy, but that's hardly a WonderSwan.

ok ill be more descriptive. im trying to either convert a *.wsc rom into a *.smc rom or get an emulator that is snes but can run wonderswan color roms as well since i heard there is one

Ok.

1) Like it was said earlier, you can't "convert" games from one system to another without reprogramming (read: coding from scratch and porting) the game.
2) Again, like it was said earlier, the SNES doesn't support the WonderSwan in any form.

Just go and download a WonderSwan emu and be done with all this SNES mess!

The file extensions on roms are just to know what kind of rom it is. But they are not like let's say a .doc to .xls or something. What Snes emu are you using?