Seems pretty simple to devise a game plan. Here are are my strat-a-gems (a gem of a strategy).
1. Short term strat-a-gem: Take a bit off 1st serve - you want to get 2 of 3 1st serves in so you don't let the guy use his good FH on your weak 2nd serve
2. Long term strat-a-gem: work on a topspin/kick 2nd serve that you can swing at at 90% of you 1st serve racket speed but brush it for more spin. Work on placement to the corners and a body serve with this new 2nd serve. Hit at least 2 buckets per week of 2nd serves.
3. Short term strat-a-gem: come to the damn net against the guys BH. His slice will not be an effective pass, his topspin pass sounds a bit wild and error prone, and for every time you come in that is one less chance for him to spank one of your short balls.
4. Short term strat-a-gem: on duece court serve him wide to open up his BH side
5. Short term strat-a-gem: hit hard cross court FH to open up his BH side
6. Short term strat-a-gem: loop high topspin shots to his slice backhand to illicit short balls