[V8i VBA] Open Next .dgn file

I have created a VBA macro (code below) that opens the next .dgn file in the current folder. I created a custom tool and I run it from there. I created another, similar, macro that opens the "previous" drawing (not the previously opened dgn). It works, but I'm a novice at programming and I wonder if the code could be streamlined (better organized?) or if there is anything that I might have missed that will cause unexpected results. Any thoughts or comments would be appreciated. Thanks.

Sub OpenNextDgn()
'if Compile error = "User-defined type not defined"
'requires "MicroSoft Scripting Runtime" reference  (Tools> References)

On Error GoTo ErrorHandler

ShowCommand "OpenNextDgn"

Dim oFileSystem As Scripting.FileSystemObject
Set oFileSystem = New Scripting.FileSystemObject
Dim oFolder As Scripting.Folder
Set oFolder = oFileSystem.GetFolder(ActiveDesignFile.Path)

Dim DgnFiles() As String 'option base 1
Dim ArrayEmpty As Boolean
ArrayEmpty = True
Dim oFile As Scripting.File
For Each oFile In oFolder.Files
  If Right(oFile.Name, 3) = "dgn" Then
    If ArrayEmpty Then
      ReDim DgnFiles(1 To 1) As String
      DgnFiles(1) = oFile.Name
      ArrayEmpty = False
    Else
      ReDim Preserve DgnFiles(1 To UBound(DgnFiles) + 1) As String
      DgnFiles(UBound(DgnFiles)) = oFile.Name
    End If
  End If
Next oFile

If UBound(DgnFiles) = 1 Then
  ShowPrompt "This is the only .dgn file in current folder"
  End
ElseIf UBound(DgnFiles) > 1 Then
  Dim i As Integer
  Dim myCount As Integer
  For i = 1 To UBound(DgnFiles)
    myCount = myCount + 1
    If DgnFiles(i) = ActiveDesignFile.Name Then
      Dim ActiveCount As Integer
      ActiveCount = myCount
      Dim NextCount As Integer
      NextCount = ActiveCount + 1
      Exit For
    End If
  Next i
  
  If NextCount > UBound(DgnFiles) Then
    ShowPrompt "This is the last .dgn file in current folder"
    End
  Else
    myCount = 0 'reset
    For i = 1 To UBound(DgnFiles)
      myCount = myCount + 1
      If myCount = NextCount Then
        Application.OpenDesignFile DgnFiles(i), False, msdV7ActionUpgradeToV8
        CommandState.StartDefaultCommand
        Exit For
      End If
    Next i
  End If
End If

Exit Sub

ErrorHandler:
  MsgBox Err.Description
  ShowCommand "OpenNextDgn"
  ShowPrompt "Error-macro failed"

End Sub