a = "ABCDE5698"
For i = 1 To Len(a)
Debug.Print Asc(Mid(a, i, 1))
Next
Dim str = "ABCDE" Dim inx = 3 str = str.ToString().Remove(inx, 1)
str = str.ToString().Insert(inx, "F")
'宣告 Public Function IndexOf ( _ value As String _ ) As Integer '用途 Dim instance As String Dim value As String Dim returnValue As Integer returnValue = instance.IndexOf(value)