The GeneralDAQEvent control is an ActiveX wrapper around the Config_DAQ_Event_Message function. The Traditional NI-DAQ function reference manual and user manual have pretty good documentation for this function. In addition, the user manual has documentation for the GeneralDAQEvent control.
I'm pretty sure, however, that your problem is that the DAQCard-700 doesn't support interrupt-driven digital input, which is necessary for the event messaging to work. The DAQCard-700 just supports static digital input.
Good luck,
Joe