forward look ahead assertion

Hi 

Could you tell me whether the regexp supports forward look ahead assertion or not? If not how could we
managed to test a patter like:

abc.xyz

which I need to match exactly abc.xyz but not

abc.xyza
abc.xyzab etc...

I.e. xyz should not follow any other characters. 

In Perl we could achieve this kind of matching using pattern like: (?:abc.xyz)(?!\w)

regards
Lilantha