How to get derived class MEMBERS by name, from base class, in C#? [duplicate]

This question already has an answer here:

• Get property value from string using reflection in C# 10 answers

I have base class CommonClass - abstract parent. From it I have many derived classes, all have only new different members of same type ObjDescr. A shorten example

public class CommonClass
{
    // many common methods, handlers and properties
}

// many derived classes like this one
public class Orders : CommonClass
{
    public ObjDescr Date  { get; private set }
    public ObjDescr Place  { get; private set }
}

CommonClass service me well, but now i wanna to do an universal method, to which i can send any different derived child class. It will iterate some of the new derived members, knowing member names.

public SuperDuperUniversal( CommonClass UnknownDerived, string memb_name )
{
    // I do access to members now only WHEN i know the class
    Orders Order1 = (Orders)UnknownDerived;
    ObjDescr aPlace1 = Orders.Place;

    // I wanna to have access like
    ObjDescr aPlace2 = UnknownDerived.Get_ObjDescr_ByName(memb_name);
    string aPlaceName = aPlace2.Description;
}

I need to have access directly to member with name memb_name instance UnknownDerived.

Edit: I disagree that this question is duplicate with other. Solution is same, i agree. But question is different. I googled and search, before i ask it, and fail to find an answer. It will be handy, if someone else is looking to get class members of instance, from name, to find this answer.