Extracting Number of Characters

Dear Excel Community

Can someone kindly advise the best formula to use for Column C in the attachment

In Column A I have SD0350 - No. of Customers Numbers

Column B should extract SD0350 and I have used =LEFT(A2,6)

Column C should extract No. of Customers Numbers and that is where I am stuck

I have about 350 rows to perform this task.

I welcome any suggestions my friends

Thanks