Not sure if this is even possible with regular expressions (I am not a
theoretical computer scientist...). There are some extensions to
regexps which allow specification of an iterator, i.e. match the
preceding expression 1-3 times or so. With such a construct it would
be easy to obtain the effect you are desireing. Without, I doubt that
it is possible.
-- Hardy Griech, Kurt-Schumacher-Str. 25/1, D-72762 Reutlingen