Try this., This may resolve your issue. But I can't say this will be the best solution. 
if($str2=~ m/^(abc|xyz)\w{6}|^\w{3}(abc|xyz)\w{3}|^\w{6}(abc|xyz)$/){
print "true ";
}else{
print "false";
}

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In reply to Re: cool regular expression needed for matching in columns by siva kumar
in thread cool regular expression needed for matching in columns by Ben Win Lue

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