develop an thunderbird add-on (like issue tracking add-on), we pay $$

Hi,

I'm requesting who can develop me a custom add-on for Thunderbird...

we are receiving lot of emails each days, they come from different
senders but most of the time have equal keywords, this identifies for
what are us talking about (eg, ticket, or something), so the keyword
in subject is like: "#S3701" (without quotes, is always the #
followed by the S and 4 digits).

so 4 different senders can send us an email with that keyword (#S3701)
and then other 3 senders more can send us emails with other different
number (#S3702).
in that case we want an add-on for "grouping" the emails (like thread)
based in the unique keyword, so in this case will be threaded 4 emails
by one unique #S3701 and in another thread 3 emails grouped by the
keyword #S3702.

We wish a button for put it ON for the thread emails and turn OFF for sort as common emails comes.

could you develop this add-on? how much time and price for that?


thanks