Extract the last number of the string under certain conditions

[p45cal]

In the attached, in column B is a Power Query offering, just right-click somewhere in that table and choose Refresh.
This is a separate table from the original table in column A, so should you sort the table in column B, the results may no longer line up with the items in column A, even after a refresh.
So for the sake of data integrity, there's a second offering in columns E:F. This is a single table so you can sort it however you want safely. It takes its data from column A.