Find the position of the first nr in a string

Hello,

I tried searching for similar questions without any luck on the forum, hence the reason for making a new thread.

Question

Whats the easiest way finding the position of the first nr in a string?

I have a large data set with area codes where I would like to know the position of the first nr in each cell.

Ex.
A2= EASTTRK123 (position would be 8)
A3 = NORTHOBS332 (Pos would be 9)
A4: = WESTFRS343
etc...

I have been doing some research and found this one to be working; =MIN(FIND({0;1;2;3;4;5;6;7;8;9};A2&"0123456789"))

Furthermore, I would love if someone could explain the logic behind the formula above.

Thanks in advance

Jacob