It will be difficult and probably be unfair to try to use a yardstick number without adjusting it for wind strength. I note that the latest version linked above has such adjustment for the Windsurfer class div 11 boards.
It will be even more variable with a planning board at the bottom end. Sub planing you will struggle to even make the upwind mark and beat the kids trainer dinghys. In 12-15 knots you will be flying relative to most other craft.
The system has a method to work out yardsticks in reverse (Personal Yardsticks). Sail a few races and have the handicapper work it out, but keep a record of the conditions so you can link it to them.
I would suggest starting at around 80 in planing conditions and see where it puts you.
The older I get, the better I was.