We have a toilet that is positioned too close to the wall to allow for sitting comfort.
Can anyone suggest some options for moving it without moving plumbing or digging around in the floor?
If you want to move the toilet 2", you can replace the flange with an off set flange. An off set flange may or may not be used in your situation, I just can't tell you without seeing your toilet.
Need to move it more than 2", it gets more involved.
It's a job for an advanced DIYer, or call a plumber.
A toilet is mounted directly over a sewer pipe. The location of the sewer pipe dictates the location of the toilet. Other than using an offset flange (mentioned by dj1) to move it a couple inches off the center of the sewer pipe, the only way to relocate is to move the sewer pipe that it sits on. Even replacing the existing flange with an offset flange can be tricky, depending upon what piping materials are involved, the condition of your subfloor, and how accessible it all is. Usually, when a toilet is placed in an inconvenient location, it is due to a floor joist falling where the toilet was originally intended to go. Lazy plumber just puts the sewer pipe on the side of the joist, moving the toilet up to 6 inches off from intended location.
One more thing to consider - the water supply line, usually located on the wall directly behind the toilet - is concealed by the toilet. If you move the sewer pipe and toilet over so much that the water line becomes visible, you will probably end up needing to move that line, too.
You could just loosen the toilet bolt and turn the toilet ever so slightly away from the wall. this providing that the water connection is a flexible braided hose connection.
A standard toilet flange will give you around 1" misalignment without problems; beyond that the flange needs to be moved. Standard toilet rough-in calls for 12" from the back wall but I know people might add tile or install wainscoting so I rough in at 12 1/2" to help allow for the future possibilities. Coupled with the 'allowed' misalignment it almost always keeps you out of trouble and it's hardly noticeable beforehand.