search for: _18xxxxxxxx

Hi Is there anyway to add logic to dialplan pattern matching? I would like to match all toll free numbers with one pattern, so 1800, 1877, 1866, 1855, etc. I can't figure out how to do this in dialplan syntax. As a programmer, I want to say 18[00 or 77 or 66 or 55 etc]. Can't figure out if this is even possible with dialplan pattern matching (though I suspect it is somehow). Andrew