use strict;
my $str = '<a href="http://domain.com/path" target="_blank">GSPd å½¹ã«ç«‹ã¤ãƒ„ール: スã‚ãƒ«æ„æ¬²ãƒžãƒˆãƒªã‚¯ã‚¹</a>';
my $regex = qr/(<[^>]*>)+([a-z][a-z ]+)/ip;
my $subst = '$1<span class="text=arial">$2</span>';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html