Don't move him, let him go where he needs to go! Since it's a photosythetic creature it will move to light. If it is hiding then something made it hide! Too much current, a sore foot already, or something. Hopefully you have the right lighting and excellent water conditions so when it is ready it can come out and thrive, if not it may be dying already. You can't make an anemone go where you want it, it has to pick a spot that is right for it!