[Intercept]
public string Method1(POS pos, int param1, string param2)
{
    return String.Format("{0}: {1}", param1,param2);
}

[Intercept]
public int Method2(POS pos, int param3)
{
    return param3 * 2;
}

public void OnPreProcessing(...)
{
     // Before Mothod1 and Method2 called, It should enter here
     // I want to be able to cancel method execution and return another value.
     // I want to get the method name, parameter names and values
}

public IMessage SyncProcessMessage(IMessage msg)
{
    var mcm = msg as IMethodCallMessage;
    OnPreProcessing(ref mcm);
    var retMsg = _NextSink.SyncProcessMessage(msg) as IMethodReturnMessage;
    OnPostProcessing(mcm, ref retMsg);
    return retMsg;
}