Yuo can use the SendMessage API with the WM_SETTEXT Constant, ie.
Code:
Private Declare Function SendMessage Lib "user32" Alias "SendMessageA" (ByVal hwnd As Long, ByVal wMsg As Long, ByVal wParam As Long, lParam As Any) As Long
Private Const WM_SETTEXT = &HC

Private Sub Command1_Click()
    Dim sText As String
    sText = Text1
    Call SendMessage(lHwnd, WM_SETTEXT, Len(sText), ByVal sText)
End Sub
Where lHwnd is the WindowHandle of the Textbox in the 3rd Party App.


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Aaron Young
Analyst Programmer
[email protected]
[email protected]