如何開啟一個檔案夾並選中指定檔案

很簡單，調用explorer.exe就可以，例如要開啟H:/CD1並且選中其中的readme.rtf：
Private Sub Command1_Click()
    Shell "Explorer /select, H:/CD1/readme.rtf", vbNormalFocus
End Sub

[Windows Explorer Switches]
Windows Explorer switches are useful in creating rooted folders:

     Explorer [/e][,/root,<object>][[,/select],<sub object>]

/e
   Use Explorer view (scope and results pane view). The default is
   Open view (results in pane view only).

/root<object>
   Specify the object in the "normal" name space that is
   used as the root (top level) of this Explorer/Folder (i.e., local
   path or UNC name). The default is the Desktop).
/Select
   The parent folder opens and the specified object is selected.
   <sub object>   Specify the folder unless /select is used. The
   default is the root.