I want to send data from my website to SIM900

This is the primary task I have set for this my little project and this is how far I have gone..
I want a standalone processor that can do the following:

  1. Receive SMS ---------- SOLVED
  2. Read the SMS as in get, sender number, message content and timestamp -----UNRESOLVED
    3a. Send the SMS to a database on my website -------------- SOLVED
    3b. Delete SMS from the SIM card -------------- UNRESOLVED
  3. Use the SMS for operation on my website ------------------ SOLVED
  4. Send data to Arduino/SIM900 to make a phone call based on the operation in 4 above. -------------UNRESOLVED

The ones marked SOLVED has been completely resolved, but the ones not completely resolved is remarked UNRESOLVED. This is what I am trying to achieve and I need it to be automated. I will like to know if I am using the right approach and device. Your assistance will be highly appreciated.

Thank you for your time and concern.