C# Application for PDA-How to start

I am thinking how to develop C# application for My PDA.
The full details of my PDA is


I am trying to develop a application which will run in my PDA.When a speacial type of sms come to PDA, my application will customise the sms,read some data from database related to the sms and will send back a msg(as sms) to the sms sender....

I am new in this type of application... so if someone give me a proper guidline that how can i start it and which type of tools(sdk,packages etc if needed) will be necessary for this type of allpication ,will be a great help for me.......

Please help me.....