chdir("C:\\some_directory") or die "$!";
opendir (DIR, ".") or die "$!";

my @files = grep{"\\*?.txt"} readdir DIR;
close DIR;

local @ARGV = @files;
while (<>) 
{
	if (/Words: /)
	{
		$somenumber = "print $_";
		$substringoffset = substr($somenumber, 26);
		open MYFILE, ">>","C:\\some_directory\\Results.csv";
		print MYFILE $substringoffset;
	}

}