Hello kanth,
It sounds like you want to do some sort of combination of analog intput and output. If this is the case, the best place for you to start is by opening up the examples for DAQ that come with LV. Just open up a VI in LabVIEW and got to "Help >> Find Examples..." in the menu bar. From there, you can browse to the folders with the appropriate examples. I recommend browsing to "Hardware Input and Output >> DAQmx >> Analog Generation" and "Hardware Input and Output >> DAQmx >> Analog Measurements".
I hope this helps!
E.Lee
Eric
DE For Life!