Hi - I am new to this forum and i am hoping that some of you experts can
help me out with this really tricky problem.

We have a weed that grows out from under the block paves on the drive -
it is green and looks like little Christmas trees - or like the ends of
the branches of the Christmas tree. A sort of brown twig like centre
spine with green blades coming of in a herringbone style.

This, perhaps?
http://www.agf.gov.bc.ca/cropprot/hrsetail.htm
http://www.hdra.org.uk/organicweeds/...weed.php?id=10
http://www.rhs.org.uk/advice/profiles0705/equisetum.asp