$number_to_dial = '555-1111';
$number_to_dial .= ',,,,';  # Let the service answer.
$number_to_dial .= '1';     # Dial "1" to send a message.
$number_to_dial .= ',';     # Small pause.
$number_to_dial .= '911';   # The number to display on the pager.

# Taken from link in Joost's post:
print TTY "atm0dt$number_to_dial\r";
sleep 10;
print TTY "\r";
print TTY "atz\r";