Delete Rows not containing string

I have a download of security groups from Active Directory.  I want to delete rows which do not contain the string:

domain.local/group/group/

Example:
Column A          Column B
Group                 Container
group A                 domain.local/group/group/group A
group B                 domain.local/group/group/group B
group C                 domain.local/group/group/group C
group D                 domain.local/group/group/group D
group E                 domain.local/group/group/group E
group F                  domain.local/group/group/group F
group G                 domain.local/group/group/group G
group H                 domain.local/group/group/group H
group I                 domain.local/group/group/group I
Group J                 domain.local/builtin/Group J
Group K                 domain.local/builtin/Group K
Group L                 domain.local/builtin/Group L
Group M                 domain.local/builtin/Group M
Group N                 domain.local/builtin/Group N

I have tried the following VBA but I can't seem to get it to work properly

Sub sbDelete_Rows_IF_Cell_Cntains_String_Text_Value()
Dim lRow As Long
Dim iCntr As Long
lRow = 20
For iCntr = lRow To 1 Step -1
    If Cells(iCntr, 1) <> "domain.local/Builtin/" Then
        Rows(iCntr).Delete
    End If
Next
End Sub
group G      domain.local/group/group/group G
group H      domain.local/group/group/group H
group I      domain.local/group/group/group I
Group J      domain.local/builtin/Group J
Group K      domain.local/builtin/Group K
Group L      domain.local/builtin/Group L
Group M      domain.local/builtin/Group M
Group N      domain.local/builtin/Group N