You could replace occurances of "webmaster" that are not proceeded by a "mailto:" with look behind assertion like this: 
$html =~ s#(?<!mailto:)(webmaster)#<htmlcode>$1</htmlcode>#gs;

[download]

for anything less specific than that you should use a module to parse html.

In reply to Re: Tricky regexp... by thunders
in thread Tricky regexp... by ti-source

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