Does this do what you want? I have used ! instead of space to make it easier to count.

Update: Finally grasped the feature that the OP wanted and wasn't getting: In addition to substituting spaces, maintain the same number of lines. Like this: 

$_ =<<'EOS';
</TABLE>

2
<PAGE>

RISK/RETURN SUMMARY AND FUND EXPENSES


PRIME MONEY MARKET FUND
EOS

my $pat = qr/(\n\s*[0-9]{1,3}\s*\n\s*<page>\s*\n\s*)(.*\n)/i;

s{$pat}{
  my ($m1, $m2) = ($1, $2);
  my $num_lines = $m1 =~ tr/\n//; # Just counting lines
  $m1 =~ tr//!/c; # Replacing all chars with ! (for visibility; use sp
+ace instead in final code)
  $m1 . $m2 . "\n" x $num_lines;
}gie or warn "No match!\n";

print;

[download]
Output is: 
</TABLE>!!!!!!!!!!!!RISK/RETURN SUMMARY AND FUND EXPENSES







PRIME MONEY MARKET FUND

[download]
Caution: Contents may have been coded under pressure.

In reply to Re: Replacing the pattern by Roy Johnson
in thread Replacing the pattern by agynr

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