pushing into struct array at a particular index

Question

Question 1: What i am trying to make is an array of struct "someStruct" which will be "someStructs". Now i am setting some values in the struct array at index "_prop1" in "createSomeStruct()". Now if i want to set further values of the struct at the same index "_prop1", which i am trying to do in addUsers function. How will i do that?

Question 2: Is it possible to have a mapping inside the struct, if yes how can we do that, if you could direct me to some documentation or example for that.

pragma solidity ^0.4.10;

contract A {

    struct someStruct{
        uint prop1;
        uint prop2;
        address [] users;
    }


    mapping (uint => someStruct) public structList;
    someStruct[] public someStructs;

    function createSomeStruct(uint _prop1, uint _prop2){
        structList[_prop1].prop1 = _prop1;
        structList[_prop1].prop2 = _prop2;
        someStructs.push(structList[_prop1]);
    }

    function addUsers(uint _prop1, address _userAddress){
        structList[_prop1].users.push(_userAddress);
        //....?

    }
}