Support for config wildcards

I would like to use our update hook to send email to recipients based on a branch name pattern. For example, the "abc" team would get email for all updates to branches that start with the word "abc".

I would like to write something like this in the config file:

[hooks.mail.recipients]
        xyz.pickle = me, you, betty-sue
        xyz* = joe, jaya, julie
        abc* = mark, nancy, svetlana
        taug* = sridhar, pete, joe
        * = me, you, big-boss

Then, in the update hook, do something like this (very pseudo-code-ish):

    for key, value in $(git config --get-regexp hooks.mail.recipients*); do
        key=${key#hooks.mail.recipients}
        if $(matches $key $branch); then
            recipients=$value
            break
        fi
    done

Which would allow me to change the mailing list recipients based on the branch without having to update the update hook each time.

But, apparently at least the '*' and '.' characters are not allowed as keys, and I can't seem to escape them.

Is there a way to do this sort of thing that I am missing?

Bill