Public Class Tester
Public Shared Sub Main
Dim quote As String = "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa"
Dim charArray() As Char = CType(quote, Char())
charArray(6) = "!"c
Dim result As String = New String(charArray)
Console.WriteLine(result)
End Sub
End Class
aaaaaa!aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa