if ($file1[0] eq $dealerno)
{
  @file2[$cnts++] = $file1[0];
  @file2[$cnts++] = $file1[1];
  @file2[$cnts++] = $file1[2];
  @file2[$cnts++] = $file1[3];
  @file2[$cnts++] = $file1[4];
  @file2[$cnts++] = $file1[5];
  @file2[$cnts++] = $file1[6];
  @file2[$cnts++] = $file1[7];
  @file2[$cnts++] = $file1[8];
  @file2[$cnts++] = $file1[9];
  @file2[$cnts++] = $file1[10];
}

##</code><code>##

if ($file1[0] eq $dealerno)
{
  @file2[0..10] = @file1[0..10];
}

##</code><code>##

Scalar value @file2[$cnts++] better written as @file2[$cnts++] at -foo.pl line 327.