Can I create my own formula for calculated field in Sharepoint 2010 using C#

I want to create a programmatically calculated field for Sharepoint 2010 using Visual Studio 2010 in C# language.

Is there a way to set a formula that will call to my own function and return a result back to the field?

My scenario:

• let's say I want to create a field that always returned the sum between two other fields,
• but I don't want to use something like "=sum([filed1],[field2])".
• I want to call to function "calc2Fields()" and return a result.

Is it possible?

No, it is not possible. By changing the formula you are not adding any internal logic, so the field will not know what to do with your function. You can however build a custom field and incorporate there any logic you need. Of course it is not going to be identical to the built-in calculate field, but then you can add your own functions.