'In your form
Option Explicit
Private Sub Form_Load()
'
Dim hwnds() As Long
Dim h As Long
Dim i As Byte
Call FindWindowLike(hwnds(), 0, "*Instant Message*", "*", Null)
For i = 0 To UBound(hwnds)
If hwnds(i) <> 0 Then
h = FindWindowEx(hwnds(i), 0, "RICHEDIT", "")
Call SendMessage(h, WM_SETTEXT, 0, ByVal "test")
Exit For
End If
Next
'
End Sub
'In a module
Option Explicit
Private Const GWL_ID = (-12)
Global ProgHandle As Long
Private Const GW_HWNDNEXT = 2
Private Const GW_CHILD = 5
Public Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Public Declare Function FindWindowEx Lib "user32" Alias "FindWindowExA" (ByVal hWnd1 As Long, ByVal hWnd2 As Long, ByVal lpsz1 As String, ByVal lpsz2 As String) As Long
Public Const WM_SETTEXT = &HC
Declare Function SetFocusAPI Lib "user32" Alias "SetForegroundWindow" _
(ByVal hwnd As Long) As Long
Private Declare Function GetWindow Lib "user32" (ByVal hwnd As Long, _
ByVal wCmd As Long) As Long
Private Declare Function GetWindowLW Lib "user32" Alias "GetWindowLongA" _
(ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function GetParent Lib "user32" (ByVal hwnd As Long) As Long
Private Declare Function GetClassName Lib "user32" Alias "GetClassNameA" _
(ByVal hwnd As Long, ByVal lpClassName As String, ByVal nMaxCount As Long) As Long
Private Declare Function GetWindowText Lib "user32" Alias "GetWindowTextA" _
(ByVal hwnd As Long, ByVal lpString As String, ByVal cch As Long) As Long
Declare Function GetDesktopWindow Lib "user32" () As Long
Declare Function GetExitCodeProcess Lib "kernel32" _
(ByVal hProcess As Long, lpExitCode As Long) As Long
Declare Function OpenProcess Lib "kernel32" _
(ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, _
ByVal dwProcessId As Long) As Long
Declare Function CloseHandle Lib "kernel32" _
(ByVal hObject As Long) As Long
Declare Function SysSetFocus Lib "user32" Alias "SetFocus" _
(ByVal hwnd As Long) As Long
Public Const WM_COMMAND As Long = &H111
Function FindWindowLike(hWndArray() As Long, ByVal hWndStart As Long, WindowText As String, Classname As String, ID) As Long
Dim hwnd As Long
Dim r As Long
' Hold the level of recursion:
Static level As Long
' Hold the number of matching windows:
Static iFound As Long
Dim sWindowText As String
Dim sClassname As String
Dim sID
' Initialize if necessary:
If level = 0 Then
iFound = 0
ReDim hWndArray(0 To 0)
If hWndStart = 0 Then hWndStart = GetDesktopWindow()
End If
' Increase recursion counter:
level = level + 1
' Get first child window:
hwnd = GetWindow(hWndStart, GW_CHILD)
Do Until hwnd = 0
DoEvents ' Not necessary
' Search children by recursion:
r = FindWindowLike(hWndArray(), hwnd, WindowText, Classname, ID)
' Get the window text and class name:
sWindowText = Space(255)
r = GetWindowText(hwnd, sWindowText, 255)
sWindowText = Left(sWindowText, r)
sClassname = Space(255)
r = GetClassName(hwnd, sClassname, 255)
sClassname = Left(sClassname, r)
' If window is a child get the ID:
If GetParent(hwnd) <> 0 Then
r = GetWindowLW(hwnd, GWL_ID)
sID = CLng("&H" & Hex(r))
Else
sID = Null
End If
' Check that window matches the search parameters:
If sWindowText Like WindowText And sClassname Like Classname Then
If IsNull(ID) Then
' If find a match, increment counter and
' add handle to array:
iFound = iFound + 1
ReDim Preserve hWndArray(0 To iFound)
hWndArray(iFound) = hwnd
ElseIf Not IsNull(sID) Then
If CLng(sID) = CLng(ID) Then
' If find a match increment counter and
' add handle to array:
iFound = iFound + 1
ReDim Preserve hWndArray(0 To iFound)
hWndArray(iFound) = hwnd
End If
End If
End If
' Get next child window:
hwnd = GetWindow(hwnd, GW_HWNDNEXT)
Loop
' Decrement recursion counter:
level = level - 1
' Return the number of windows found:
FindWindowLike = iFound
End Function