Get unique letters sorted

Improved code

Function UniqueSorted(IP As String)
Dim L As Long, T As Long, Ta As Long, K As Long
Dim A(1 To 26)
Dim S As String, Rslt As String

L = Len(IP)
For T = 1 To L
S = LCase(Mid(IP, T, 1))
K = InStr(1, "abcdefghijklmnopqrstuvwxyz", S)
If A(K) = "" Then A(K) = Mid(IP, T, 1)
Next T

For Ta = 1 To 26
Rslt = Rslt & A(Ta)
Next Ta
UniqueSorted = Rslt
End Function