Yes, you can use Qt Mobility for this. I use it in my silly SMSPetFeeder project to check through the message of each sms text received for the trigger word "Doggytreat". For the project I implemented a helper class to handle the sms messages, you can see the code I used in the 'making of' project video. You can use the same code as a starting point for your own project to intercept the SMS and do whatever you need with it.

Or you can just watch me feeding dogs with it here

Intercepting the sms messages will probably be the easiest bit, it's all the other stuff you want to do after that may be more tricky.