You want to measure temperature with thermocouple, than to convert that with adc and to read with labview via RS232.
First of all thermocouples gives very small voltages over temperature range, a few mV, so first you have to amplify this voltage to some range e.g. 0-5V.
This could be tricky because you need big gain and consequently you amplify and tempearure signal and all noise around...
Generally you have to build thermocoupler to RS232 converter, this will be much easier with mcu. Please think again about non using mcu.
Labview must have some RS232 protocol,so, you have to make that your converter interpret measured temperature in some fixed message format.
Mr.Cube