If I understand you correctly you want to trigger one of the data input pins of the SmartIO by software.
Yes, that is possible by configuring the data pin as input with "undefined" source. Select synchronous or asynchronous input as you need. Now you can manipulate the signal by setting the corresponding GPIO high or low, as smartIO is not bypassed, the signal will not be shown at the GPIO pin. So you basically cut open the connection from the GPIO registers to the GPIO pin.
The GPIO signal will then be controlled by the corresponding LUT if the "gpio" is configured as output.