How about this? The range operator will allow you to skip (not remove) lines up to (and including) the matching line. 
use strict;

while (<DATA>)
{
  next if 1../^CPN/;

  #-- Parse lines...
  print;
}


__DATA__
BOM Report 
------------------- 
BOM  : 
Date : 19 Sep 2001 14:57:17 
Total # of CPN's (41) 
----------------------- 
CPN Quantity MPN Vendor 
51-0597-000 15 06035C103MAT2A AVX 
51-0597-000 15 06035C103MAT4A AVX 
51-0597-000 15 C0603C103M5RAC KEMET ELECTRONICS

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In reply to Will the range operator help you? by Rhose
in thread How to remove lines out of an ascii file by juo

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