Reference: Cocoa Event Handling Guide
The above Mac Developer Library guide does not state any known methods to programmatically generate Touchpad Gestures.
It goes so far as to say the touchpad gestures themselves occur outside of the OS:
"The trackpad hardware includes built-in support for interpreting common gestures and for mapping movements..."
That guide also explicitly mentions apps should not rely on that sole input mechanism, and it's best to include support for keyboard and mouse for that reason.
Now that Mac and Windows (i.e., Windows 8) are supporting touchscreen monitors at the OS level, it's a matter of time before programmatically touchpad & touchscreen gestures can be incorporated into services like your project or remote desktop control using the appropriate API when it becomes available.