PHP - da vb a php

Qualcuno mi pu? trasformare questo codice VB a PHP?? PLS. ? urgente....



Public Function LockToKey(lck As String) As String
Dim h As Integer, j As Integer, n As Integer
n = 5
h = InStr(1, lck, " "
If h Then lck = Left$(lck, h - 1)
h = Asc(lck) Xor Asc(Right$(lck, 1)) Xor Asc(Right$(lck, 2)) Xor n
h = (h \ 16) Xor (h * 16)
Do While h > 255
h = h - 256
Loop
Select Case h
Case 0, 5, 36, 96, 124, 126
LockToKey = "/%DCN" & Right$("00" & CStr(h), 3) & "%/"
Case Else
LockToKey = Chr$(h)
End Select
For j = 2 To Len(lck)
h = Asc(Mid$(lck, j, 1)) Xor Asc(Mid$(lck, j - 1, 1))
h = (h \ 16) Xor (h * 16)
Do While h > 255
h = h - 256
Loop
Select Case h
Case 0, 5, 36, 96, 124, 126
LockToKey = LockToKey & "/%DCN" & Right$("00" & CStr(h), 3) & "%/"
Case Else
LockToKey = LockToKey & Chr$(h)
End Select
Next
End Function

trasformato da solo.
Con un pu? di fatica ci sono riuscito....
he eh eh