I am using Canon Autoboy Luna (28-70mm) with Fuji Superia Premium 400. About 20 shots after, I accidentally rewind the roll. Is there anyway that I could manually advance the roll to the point (say 22) and continue to shot it ? Otherwise, I suppose I just have to take it out and bring it to the shop to develop it.
There does not appear to be a way to "manually advance" the film or take photos with the lens cover closed. You could go into a completely black room/closet ( no light what so ever). You could also wrap the camera in a black cloth just in case there are any light leaks in the room/closet.
Turn OFF the flash and push the shutter button just like you were taking photos until you reach 23. You will need to count in your head the number of shots up to 23 plus one for good measure.
Or if you have a good lab they may be able to clip off the exposed portion of shots for development and leave the remainder in the cassette for you, does not hurt to ask.