You change the code that creates the HTML string to set the value outside of the interpolation:

my %descriptions= (
    'level3' => 'level3 stage',
    'level2' => 'level2 stage',
    'level1' => 'level1 stage',
);
my $visual= $decsriptions{ $string } || 'Edit';

...

print "<td align=center>&nbsp;$visual</td>
[download]

Maybe it would be a good time now to look at templating systems.