黑客大叔的解法是
Private Function ifget(ByVal x As String, ByVal y As String) As Boolean
If y.IndexOf(x) <> -1 Then
ifget = True
ElseIf x.IndexOf(y) <> -1 Then
ifget = False
ElseIf y.IndexOf(x) = -1 Then
'当互相都不存在对方时，函数返回 默认值 false
' MsgBox("两者互相都不在！")
ElseIf x.IndexOf(y) = -1 Then
'当互相都不存在对方时，函数返回 默认值 false
' MsgBox("两者互相都不在！")
End If
End Function

另一种是
Private Function ifget(x As String, y As String) As Boolean
If x = "" Or y = "" Or Len(y) > Len(x) Then Exit Function
ifget = True
Dim i As Integer
For i = 1 To Len(x) - Len(y) + 1
If Mid(x, i, Len(y)) = y Then
ifget = False
Exit For
End If
Next
End Function