[Texan5]

At this point, I'd yank out the offending spindle(s), deal with the screw, and go to the lumber yard with the spindle to find one that at least half ass matches it, then install and paint it to match the others...Of course, if that happens to me, I will just go out to hubby's workshop and get another baluster (spindle), seal it with urethane and install it. Since he made all the parts for the stairway and loft rail, he made sure we had some extra balusters, top rail, etc. We've already had to replace one that the dogs chewed on when they got accidentally trapped upstairs and were bored.

[hobbes1]

If you cant match it, you could cut it with a coping saw, pull it out from the middle, deal with the screw... and put it back with glue....then sand and paint.