Option Explicit

Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" ( _
                    ByVal Hwnd As Long, _
                    ByVal lpOperation As String, _
                    ByVal lpFile As String, _
                    ByVal lpParameters As String, _
                    ByVal lpDirectory As String, _
                    ByVal nShowCmd As Long) As Long

function fOpenFile(sFPath As String) as boolean
    On Error Resume Next    
    fOpenFile = ShellExecute(0&, "Open", sFPath, _
                           vbNullString, vbNullString, 1&) > 32    
End Sub

' использовать функцию так:
sub UsingOf()
   if not fOpenFile("здесь_полный_путь_к_файлу") Then
       msgbox "не удалось открыть файл!"
   end if
end sub

ThisWorkBook.FollowHyperlink FullFileName   ' FullFileName - полный путь к файлу

Function ExistFile(FullFileName$) As Boolean : ExistFile = Dir(FullFileName) <> "" : End Function