I like this approach, but it's hard not to use sprintf in this case:

my $tab = 8;

while (<DATA>) {
    chomp;
    my @fields = split(/\t/, $_);
    my $cooked = shift (@fields) . join '', sprintf("-$tab%s", @fields
+);
    print $cooked, "\n";
}
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lhoward's looks more elegant, though. Make it use variable tabstops like so:

my $tab = 8;
s/\t/" " x $tab/ego;
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