You can get a bit fancier with this regex and use positive and negative lookahead/lookbehind, which gives you a chance to take care of the most common proper names in the book as well:
(?<=[a-z])(?= [A-Z](?!(obert|avid|ebecca)))
Use the trailing characters of the proper name (i.e. remove the first letter) in the last set of parentheses, sepearated by '|' in case that's not obvious above. Then you only need to use this for replacement:
.
|