Hi Stn,
You would need to use SCCP for these features to work;
Check out Table 1 from this VG224 doc (show SCCP support for Conference);
http://www.cisco.com/en/US/products/hw/gatecont/ps2250/products_data_sheet09186a00801d87f6.html
Conference Call
Initiates a three-party conference.
During an active call, user presses hookflash for dial tone, dials a third party, and then presses hookflash again to connect all three parties
From this doc;
http://www.cisco.com/en/US/products/ps6441/products_feature_guide09186a0080483a76.html#wp1178205
Hope this helps!
Rob
PS: How did you make out with the DST Emergency? I did respond to one of your posts but I never heard back to see if your issue was resolved :)