Mapping string to method call in c# [duplicate]

Suppose there are these classes:

class A    
{    
    public string someField="something";        
    public void MethodA(){}     
}

class B
{
    public A propertyA;
}

class C
{
    public B propertyB;
    string s1 = "propertyB.propertyA.MethodA()";        
    string s2 = "propertyB.propertyA.someField";
    public void Method()
    {
        //so for s1 it does
        propertyB.propertyA.MethodA();
        //and for s2 it does
        var something = propertyB.propertyA.someField;
        //or
        propertyB.propertyA.someField = "somethingNew"
    }
}

How can I execute a method in class A from class C represented as string s1 and get or assign value to someField(s2)?