Extract date from subject and pass it to a custom field

Hello,

We have given our customers a standard subject line that they can use to raise tickets. Something like this: Booking No. // Request Type// MM-DD-YYYY

I want to extract the MM-DD-YYYY and pass that value to a custom field so that we can run SLA based on this field and prioritize case accordingly.

Please point me in the right direction on how to do this, thanks!