ComboBox to type on specific window - vb.net

Question

I can't figure out how to make my ComboBox (which lists all open windows(I can see these already)) to make my form type on that selected window. I just can't make it so when screen1 is selected, it clicks on that screen.
Example:
I have 2 different forms open.
Form (1) clicks on a specified screen. (screen1)
Form (2) clicks on a different specified screen. (screen2)
The forms are the same program just opened twice.
I want my form to be able to click on a certain screen even if it's not open.
Imports System.Runtime.InteropServices
Imports System.Diagnostics
Public Class W1
Public Declare Function EnumWindows Lib "user32.dll" (ByVal lpEnumFunc As EnumWindowsProc, ByVal lParam As Int32) As Int32
Public Declare Function IsWindowVisible Lib "user32.dll" (ByVal hwnd As IntPtr) As Boolean
Public Delegate Function EnumWindowsProc(ByVal hwnd As IntPtr, ByVal lParam As Int32) As Boolean
Public Declare Function GetWindowText Lib "user32.dll" Alias "GetWindowTextA" (ByVal hwnd As IntPtr, ByVal lpString As String, ByVal cch As Int32) As Int32
Public Declare Function GetWindowTextLength Lib "user32.dll" Alias "GetWindowTextLengthA" (ByVal hwnd As IntPtr) As Int32
Public Declare Function GetWindowLong Lib "user32.dll" Alias "GetWindowLongA" (ByVal hwnd As IntPtr, ByVal nIndex As Int32) As Int32
Public Declare Function GetParent Lib "user32.dll" (ByVal intptr As IntPtr) As IntPtr
Private Declare Function GetWindowRect Lib "user32.dll" (ByVal hWnd As IntPtr, ByRef lpRect As RECT) As Boolean
Public Property SelectedItem As Object
Public Const GWL_HWNDPARENT As Int32 = -8
Private newwindowlist As List(Of String)
Private newhandlelist As List(Of IntPtr)
Private Structure RECT
Public left As Integer
Public top As Integer
Public right As Integer
Public bottom As Integer
Public Sub New(ByVal _left As Integer, ByVal _top As Integer, ByVal _right As Integer, ByVal _bottom As Integer)
left = _left
top = _top
right = _right
bottom = _bottom
End Sub
End Structure
Private Function EnumWinProc(ByVal hwnd As IntPtr, ByVal lParam As Int32) As Boolean
If IsWindowVisible(hwnd) Then
If GetParent(hwnd) = IntPtr.Zero Then
If GetWindowLong(hwnd, GWL_HWNDPARENT) = 0 Then
Dim str As String = String.Empty.PadLeft(GetWindowTextLength(hwnd) + 1)
GetWindowText(hwnd, str, str.Length)
If Not String.IsNullOrEmpty(str.Substring(0, str.Length - 1)) Then
newwindowlist.Add(str.Substring(0, str.Length - 1))
End If
End If
End If
End If
EnumWinProc = True
End Function
Private Sub RefreshWindowList()
newwindowlist = New List(Of String)
EnumWindows(AddressOf EnumWinProc, CInt(True))
End Sub
And
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
RefreshWindowList()
For Each item As String In newwindowlist
ComboBox1.Items.Add(item)
ComboBox1.SelectedItem = Convert.ToInt64(GWL_HWNDPARENT)
Next
End Sub