[thelist] writing to a file PHP (csv)

Hi All

I have a little bit of code that writes info to a file and wondered if someone
could just point me in the direction for outputting the data to the said file in
csv format so it's ready to import inot sage line 50 I believe.  This is what I
have so far.  However it isn't putting the data in csv format (tab)?

$FileName="admin/email_list.txt";
		$fp = fopen($FileName, "a+");
		fputs($fp, "$cc,\n");
		fclose($fp);


Thank you
Andrew