Hi Cedric:

Sorry, I am lost here. What I understand is that the input text
is something like:

   issuexyz

the output between the a, /a tags is `[issuexyz](issuexyz)` or is
each of [issuexyz] and (issuezyz) a separate a tag?

Your url reference looks like it is a technique to return
multiple matches reusing subelements that have already
been matched. E.G. when matching three digits
for 123456 return:

   123 234 345 456

and not

   123 456
 
which is I don't see as applicable here.