User defined function in excel to Change case char by char

!................Use:- Change Case Char by Char............!

Function CHANGE_CASE(x) As Variant

Dim y As Variant
y = ""
For i = 1 To Len(x)
If Asc(Mid(x, i, 1)) > 64 And Asc(Mid(x, i, 1)) < 91 Then
y = y & LCase(Mid(x, i, 1))
Else
y = y & UCase(Mid(x, i, 1))
End If
Next
CHANGE_CASE = y

End Function



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Example:-
=CHANGE_CASE ("AbcDeFgHiJkLmNoPqRsTuVwXyZ")

Result----------------------------------->aBCdEfGhIjKlMnOpQrStUvWxYz