C#: Return a delegate given an object and a method name

Suppose I'm given an object and a string that holds a method name, how can I return a delegate to that method (of that method?) ?

Example:

MyDelegate GetByName(ISomeObject obj, string methodName)
{
    ...
    return new MyDelegate(...);
}

ISomeObject someObject = ...;
MyDelegate myDelegate = GetByName(someObject, "ToString");

//myDelegate would be someObject.ToString

Thanks in advance.

One more thing -- I really don't want to use a switch statement even though it would work but be a ton of code.