VB.net only 32 bytes and less to search - vb.net

Question

this is a function to search for a byte pattern (in process memory) in an array of bytes.
where SearchFor is the array of bytes to look for. and SearchInis the array of bytes dumped by the ReadProcessMemory external function. this is also done using Wildcard "?".
problem is if the byte pattern length is less or equal to 32 it will search. else return intptr.zero. and im not sure why.
Private Function WildCard(ByVal SearchIn As Byte(), ByVal SearchFor As Byte()) As IntPtr
Dim l As Integer = 0, m = 0
Dim iEnd As Integer = SearchFor.Length
Dim sBytes As Integer() = New Integer(&H100 - 1) {}
Dim i As Integer
For i = 0 To iEnd - 1
If (SearchFor(i) = &H3F) Then
l = (l Or (CInt(1) << ((iEnd - i) - 1)))
End If
Next i
If (l <> 0) Then
Dim j As Integer
For j = 0 To sBytes.Length - 1
sBytes(j) = l
Next j
End If
l = 1
Dim index As Integer = (iEnd - 1)
Do While (index >= 0)
sBytes(SearchFor(index)) = (sBytes(SearchFor(index)) Or l)
index -= 1
l = (l << 1)
Loop
Do While (m <= (SearchIn.Length - SearchFor.Length))
l = (SearchFor.Length - 1)
Dim length As Integer = SearchFor.Length
Dim k As Integer = -1
Do While (k <> 0)
k = (k And sBytes(SearchIn((m + l))))
If (k <> 0) Then
If (l = 0) Then
Return New IntPtr(m)
End If
length = l
End If
l -= 1
k = (k << 1)
Loop
m = (m + length)
Loop
Return IntPtr.Zero
End Function