How to make modem pause for voice mail?

[chachdogg]

I have a motorola 56k modem and I need to make it pause before dialing out so it can detect a dialtone. I have tried putting a comma and 2 and 5 commas before the number (ex: ,,T555-555-5555) but it won't do it. If I pick up the phone, and then click dial, it works no matter what I have in front of it.
There is a section in the modems control panel applet that gives me the option to add commands but I dont know what to type.

[Gargomel7]

W -- Wait for a Subsequent Dial Tone. The W dial modifier causes a modem to wait for an additional dial tone before dialing the numbers that follow the W. The length of time the modem waits depends on the value in S-Register S7. The modem can be instructed to dial through ***s (Private Branch Exchanges) or long-distance calling services that require delays during dialing. This can be done with the W command to wait for a secondary dial tone or with a comma (,) command to pause for a fixed time and then dial. Ex: ATDT 9 W 1 2155551212 [Enter]