Can I make my cursor move using Unity in Source games?

I play a game called CS:GO and I was wondering if it was possible to move my cursor within the game. CS:GO is made by valve and runs on the Source engine. At the minute, I am able to move my cursor through code while window focus is on Unity or Google Chrome. I do have "Run In Background" checked.

Here is my current code:

 using UnityEngine;
 using System.Collections;
 using System.Drawing;
 using System.Runtime.InteropServices;
 
 public class MouseControl : MonoBehaviour {
 
     [DllImport("user32.dll")]
     public static extern bool SetCursorPos(int X, int Y);
     [DllImport("user32.dll")]
     public static extern bool GetCursorPos(out Point pos);
 
     Point cursorPos;
 
     // Use this for initialization
     void Start () {
         cursorPos = new Point();
         GetCursorPos(out cursorPos);
         Invoke("moveMouse", 3);
     }
 
     void moveMouse() {
         SetCursorPos(cursorPos.X, cursorPos.Y + 150);
     }
 }
 

I have not yet compiled this, but I don't think that is the problem.

Thanks in advance, and I am really sorry if this is just a noob question.