my $parameterFound = 0;                                      # the flag

while( my $line = <@data> )         # your code that claims to read the file line-by-line
{
	if ($line =~ /Parameter/)  { $parameterFound = 1 ;}  # start reading real data now
	next if ($parameterFound == 0);                      # we are still in the header
	print ....
}