Simply put, no. The bandwidth required for a webcam will be much larger than you could sensibly put over serial. OK I know you can get >2MBaud of out an FT232R (with a suiteable RS232 Line driver), but that will still absolutely prevent video and make still images slow.
Fundamentally the USB Camera is a device and must connect to a USB host. The WiFi module (from the information you give) is not a USB host.
If you obtain a Raspberry Pi, you could probably use that as it is a USB host to which you can connect your camera and an ethernet (or your WiFi) module. (I only say probably as you didn't give the make/model of camera, so I don't know if suitable software is available for the Pi)