[Q] How to parse SMS and send customized response topic

I have a need to respond to an SMS whether I'm at the phone or not.

The SMS will be something along the lines of:

Quote:

ABC shift available: Monday 02/23/2015 07:30->16:30 NAME_OF_SHIFT REPLY "398" TO CONFIRM Your booking will be confirmed by another SMS.

The text comes in the day before a shift. If you're at work when the text comes in, you can't respond, and you'll lose out on getting to work the next day. So I'd like a way to look at the text, see if it matches certain conditions, then respond if desired. Ideally I could have it check several things; if the "NAME_OF_SHIFT" is one I'd like, it can ignore the rest of the message, I definitely want to take it. If "NAME_OF_SHIFT" is one I'm not as fond of, it can look at the time listed (i.e. 07:30->16:30 would be accepted, but not a 20:30-07:30). Once it's done it's parsing, if it matches my "YES, DEFINITELY!" criteria, it'll look for the three digit number in quotation marks and will send a reply with that as the message. Then I just need to check the phone at the end of the day and see what shift it signed me up for.

*I don't think their system would try to double-book me, but it wouldn't be a bad idea if it was only allowed to respond once per day.