Looks like ics is = to vcs pretty much. Here's the file on the WNYMusic site:
Seems to me you can create a file in this format (fopen, fwrite), stick an ics extension on it, and there you go.
PRODID:Wnymusic.com Web Calendar
DESCRIPTION;ENCODING=QUOTED-PRINTABLE: Tickets available at Club Infinity Box Office (716)565-0110, Tickets.com, Tops Supermarkets. Free Parking. All shows are 18 and up (if under 18, must be accompanied by someone over 21).