Auto-populate Text User Field from message content

I would like to take a piece of content from a customer's initial message and add it to a custom user field we have. Here's a breakdown of what I'm trying to do:

When a message arrives, it always includes the following at the bottom of the ticket:

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Player ID: xxxxxxxxxxxxx
Device Info: iPhone OS 8.4.1 iPad4,1
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We then also have a field we created called "Player ID". What I would like to happen is when a ticket is first received/opened/responded to (whatever's easiest), the "xxxxxxxxxxxxx" (well, the actual number), after the words "Player ID: ", from the body of the message be automatically entered into the Player ID field. Is this type of thing possible at all?  Is there an app that does this?

Thank you in advance!