Con la ayuda de google pude hacerlo por fin
Claro, no es el real que puedes crear Splits pero funciona
Requiere solo 2 PictureBox (el de la izquierda mas chico que el de la derecha) :
Const GWL_STYLE = (-16)
Const WS_THICKFRAME = &H40000
Const SWP_DRAWFRAME = &H20
Const SWP_NOMOVE = &H2
Const SWP_NOSIZE = &H1
Const SWP_NOZORDER = &H4
Private Declare Function GetWindowLong Lib "user32" Alias "GetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long) As Long
Private Declare Function SetWindowLong Lib "user32" Alias "SetWindowLongA" (ByVal hwnd As Long, ByVal nIndex As Long, ByVal dwNewLong As Long) As Long
Private Declare Function SetWindowPos Lib "user32" (ByVal hwnd As Long, ByVal hWndInsertAfter As Long, ByVal x As Long, ByVal y As Long, ByVal cX As Long, ByVal cY As Long, ByVal wFlags As Long) As Long
Private Sub CambiarEstilo(queControl As Control)
Dim Style As Long
Style = GetWindowLong(queControl.hwnd, GWL_STYLE)
Style = Style Or WS_THICKFRAME
Style = SetWindowLong(queControl.hwnd, GWL_STYLE, Style)
Style = SetWindowPos(queControl.hwnd, Me.hwnd, 0, 0, 0, 0, SWP_NOZORDER Or SWP_NOSIZE Or SWP_NOMOVE Or SWP_DRAWFRAME)
End Sub
Private Sub Form_Load()
CambiarEstilo Picture1
End Sub
Private Sub Picture1_Resize()
Picture2.Left = Picture1.Width + 200
Picture2.Width = Form1.Width - Picture2.Left - 200
End Sub
