合并同一个文件夹中多个相同结构的EXCEL表合并在一个EXCEL表中代码不明白，请高手指教

下面的合并代码。VBA我是新手不懂，哪位高手能否逐行注释一下好吗？多谢了

Sub 合并当前目录下所有工作簿的全部工作表()

Dim MyPath, MyName, AWbName

Dim Wb As Workbook, WbN As String

Dim G As Long

Dim Num As Long

Dim BOX As String

Application.ScreenUpdating = False
MyPath = ActiveWorkbook.Path

MyName = Dir(MyPath & "\" & "*.xls")

AWbName = ActiveWorkbook.Name

Num = 0

Do While MyName <> ""

If MyName <> AWbName Then  
Set Wb = Workbooks.Open(MyPath & "\" & MyName)

Num = Num + 1

With Workbooks(1).ActiveSheet

.Cells(.Range("B65536").End(xlUp).Row +2, 1) = Left(MyName, Len(MyName) - 4)

For G = 1 To Sheets.Count

Wb.Sheets(G).UsedRange.Copy .Cells(.Range("B65536").End(xlUp).Row + 1, 1)  
Next

WbN = WbN & Chr(13) & Wb.Name

Wb.Close False

End With

End If

MyName = Dir

Loop

Range("A1").Select

Application.ScreenUpdating = True

MsgBox "共合并了" & Num & "个工作薄下的全部工作表。如下：" & Chr(13) & WbN, vbInformation, "提示"

End Sub