Here's one trick:
If you have alphanumeric strings like abc1, cdefg223 etc. then to find out first digit position one might implement:
=MIN(IFERROR(FIND({0,1,2,3,4,5,6,7,8,9},B2,1),99))
but this needs to be array entered.
To avoid array entry you've to eliminate the error which you can do by writing formula like below:
=MIN(FIND({0,1,2,3,4,5,6,7,8,9},B2&"0123456789",1))
This is normally entered formula.