I don't know how fast this is compared to possible regular expressions but this is how I'd start -- given the limited problem description -- and benchmark against other options if this (or a variant of it) isn't fast enough. 

my $input = '\one\two\three\four';
my $last = ( split /\\/, $input )[-1];
print $last, "\n";

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In reply to Re: Quick Regex Needed by Your Mother
in thread Quick Regex Needed by Anonymous Monk

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