large document multiple regex

Hello,

I am receiving a large (300k+_ document from an external agent and
need to reduce a few interesting bits of data out of the document on
an insert trigger into separate fields.

regex seems one way to handle this but is there any way to avoid
rescanning the document for each regex. One solution I am kicking
around is some C hackery but then I lose the expressive power of
regex. Ideally, I need to be able to scan some text and return a
comma delimited string of values extracted from it. Does anybody know
if this is possible or have any other suggestions?

merlin