如何将错误号捕获到变量中

Question

我已经在excel vba中编写了一个代码，它最初检查定义的word文档是否已经打开。

If IsFileOpen(pathh) Then
 MsgBox " Already in use"

 Else
 MsgBox "Not in use"

 End If


Function IsFileOpen(pathh As String)
   Dim filenum As Integer, errnum As Integer

   On Error Resume Next   ' Turn error checking off.
   filenum = FreeFile()   ' Get a free file number.
   ' Attempt to open the file and lock it.
   On Error Resume Next
   Open pathh For Input Lock Read As #filenum

   Close filenum          ' Close the file.
   errnum = Err           ' Save the error number that occurred.
   On Error GoTo 0        ' Turn error checking back on.

   ' Check to see which error occurred.
   Select Case errnum

       ' No error occurred.
       ' File is NOT already open by another user.
       Case 0
           IsFileOpen = False

       ' Error number for "Permission Denied."
       ' File is already opened by another user.
       Case 70
           IsFileOpen = True

       ' Another error occurred.
       Case Else
           Error errnum
    End Select
    End Function

但问题是，如果我在运行此代码之前已经打开word文档但是它没有被输入到选择案例代码段中，那么我得到错误70（权限被拒绝）。

而是抛出一个并停止进一步执行代码。

   Open pathh For Input Lock Read As #filenum

我想捕获错误编号并将其输入到选择案例中，在该情况下，无论文件是否打开，它都会显示相应的消息