si se puede con API,s pon en un formulario un textbox y 2 command button:
Dim window As Long
Private Declare Function FindWindow Lib "user32" Alias "FindWindowA" (ByVal lpClassName As String, ByVal lpWindowName As String) As Long
Private Declare Function ShowWindow Lib "user32" (ByVal hwnd As Long, ByVal nCmdShow As Long) As Long
Private Const SW_HIDE = 0
Private Const SW_SHOW = 5
Private Sub Command1_Click()
On Error Resume Next
window = FindWindow(vbNullString, Text1.Text)
ShowWindow window, SW_HIDE
End Sub
Private Sub Command2_Click()
On Error Resume Next
window = FindWindow(vbNullString, Text1.Text)
ShowWindow window, SW_SHOW
End Sub
Aver si esto te sirve
salu2