Take a look at the response in your Python topic with the same question for how to connect the sensor to the UE9. As for getting the reading, the process is the same in C though the calls will differ. An easy way to read the voltage is to use the eAIN function provided by the ue9.h/c code. ue9EFunctions.c demonstrates eAIN usage, and both the examples and ue9.h/c files are included in the UE9 examples directory in the Exodriver download.
A quick example (partial code and untested):
//Open the UE9 and get the calibration constants. For full code, which also provides
//the close code, refer to ue9EFunctions.c.
//Read the voltage from AIN0 which the LM35's Vout is connected to.
double dblVoltage = 0;
double dblTempC = 0;
if( (error = eAIN(hDevice, &caliInfo, 0, 0, &dblVoltage, LJ_rgBIP5V, 12, 0, 0, 0, 0)) != 0 )
//Convert to Celsius
dblTempC = dblVoltage * 100;
printf("Temperature (Celsius) = %.3f\n", dblTempC);