I do understand your point. However, the OP appears to be only interested in an exact first name match, given the data set and specific example output. Additionally, the OP says, "...I want to search for a particular first name..." (emphasis mine); sub-string matching does not return a particular first name. Based on these factors, it made sense to force an exact first name match--as the OP's desired output showed. It's certainly easy enough, however, to remove the regex's \bs if my exact-match assumption is incorrect.
Thanks for addressing this issue...
