Email subject line modification

[sspence]

Is there a way to modify the email subject line when an email comes into the gmail app?

I receive emails with specific numbers in the subject line. I would like to automatically convert that number string into a particular identifier, such as an email that has "5845" in the subject line would read "abcd" in the inbox. The account is an office 365 account using gmail to access it.

I have accomplished this in my outlook installation on the laptop, but it only works when outlook is running on the laptop, which is almost never. I would like to just automate it on my phone if at all possible.

Any ideas are appreciated.

Thanks!