Pau

You can allow filtering on a protected sheet using the following code

With Worksheets("Sheet1"
.Unprotect Password:="YourPassword
If Not .AutoFilterMode The
.Range("A1").AutoFilte
End I

.EnableAutoFilter = Tru
.Protect Password:="YourPassword",
contents:=True, userinterfaceonly:=Tru
End Wit

Regard
Rowan