Specific text IF Statement in Excel

I created a fairly simple If statement in Excel to keep track and classify some cost categories.

One of them is a set of number '8405-xxx'. I created an If(LEFT(A2950;4)="8405";"8405".

But then someone in the company decided to create 'GE8405-xxx'. Which is the same as 8405.

I did look for a while but was not able to find a formula that could return '8405'.

Thank you.