Visual Basic - se encicla.. me ayudan??

hola tengo este codigo

Declare Function OpenProcess Lib "Kernel32" _
(ByVal dwDesiredAccess As Long, ByVal bInheritHandle As Long, _
ByVal dwProcessId As Long) As Long

Declare Function GetExitCodeProcess Lib "Kernel32" _
(ByVal hProcess As Long, lpExitCode As Long) As Long

Declare Sub Sleep Lib "Kernel32" (ByVal dwMilliseconds As Long)
Public Sub ExecCmdNoFocus(ByVal CmdLine As String)
Dim hProcess As Long
Dim RetVal As Long
hProcess = OpenProcess(PROCESS_QUERY_INFORMATION, False, Shell(CmdLine, vbHide))
Do
GetExitCodeProcess hProcess, RetVal
DoEvents
Sleep 100
Loop While RetVal = STILL_ACTIVE
End Sub

y se me encicla en :

Public Sub ExecCmdNoFocus(ByVal CmdLine As String)
Dim hProcess As Long
Dim RetVal As Long
hProcess = OpenProcess(process_query_information, False, Shell(CmdLine, vbHide))
Do
GetExitCodeProcess hProcess, RetVal
DoEvents
Sleep 100
Loop While RetVal = STILL_ACTIVE
End Sub

y mas precisamente en el do... no entiendo porque el retval nunca cambia de valor.. alguien me podria ayudar??

gracias de antemano..
bye..