The best solution I can give you is to use a service like
Twilio[
^]. They will allow you to send and receive text messages through their service. It isn't free, but it is relatively inexpensive. This would allow you to sent messages to the computer.
If you were looking for alternatives, you could also get a physical card for your computer that would connect to the cell towers and get the text messages. It is more expensive than Twilio and it will be more complicated, but if you are doing a lot of text messages it might be cheaper in the long run.
If you are looking for other quick ways to send a message to your computer, you could use Twitter. Listen to a specific account and when they send a message, process it and perform the requested operation.