Applying code to entire column

Hi Guys,

I'm pretty new to vba, and i've written some code which works fine apart from i need it to run down an entire column, as it stands it's just one cell.

Here's a section of the code, it is considerably longer but it's pretty much repeating the same format just looking for different data.

Sub subConfig()
Dim subConfig As String
subConfig = "AB4"

    If Range("K4").Value = "CD" And Range("L4").Value = "1" Then
        Range(subConfig).Value = "5"
    ElseIf Range("K4").Value = "CD" And Range("L4").Value = "2" Then
    Range(subConfig).Value = "D"
    ElseIf Range("K4").Value = "CD" And Range("L4").Value = "3" Or Range("L4").Value = "4" Then
    Range(subConfig).Value = "H"
    ElseIf Range("K4").Value = "CD" And Range("L4").Value = "5" Then
    Range(subConfig).Value = "G"
    ElseIf Range("K4").Value = "CD" And Range("L4").Value = "6" Or Range("L4") = "7" Or Range("L4") = "8" Then
       Range(subConfig).Value = "R"
    ElseIf Range("K4").Value = "CD" And Range("L4").Value = "9" Or Range("L4") = "10" Or Range("L4") = "11" Or Range("L4") = "12" Then
       Range(subConfig).Value = "T"

I've tried a few a couple of ways to apply it to the column but it just seems to crash or error. Any help is hugely appreciated

Maybe

Sub subConfiguration()
Dim subConfig As String
subConfig = "AB4"

    Select Case Range("K4") & Range("L4")
        Case "CD1"
            Range(subConfig) = 5
        Case "CD2"
            Range(subConfig) = "D"
        Case "CD3", "CD4"
            Range(subConfig) = "H"
        Case "CD5"
            Range(subConfig) = "G"
        Case "CD6", "CD7", "CD8"
            Range(subConfig) = "R"
        Case "CD9", "CD10", "CD11", "CD12"
            Range(subConfig) = "T"
        Case Else
            Range(subConfig) = ""
    End Select

End Sub

You should read the forum rules and add code tags to your code extract.

However, just to make you welcome ...

Untested code:

Sub subConfig()
Dim lLR As Long
Dim i As Long
Dim subConfig As String
lLR = Range("K" & Rows.Count).End(xlUp).Row
subConfig = "AB"

For i = 4 To lLR
    If Range("K" & i).Value = "CD" And Range("L" & i).Value = "1" Then
        Range(subConfig & i).Value = "5"
    ElseIf Range("K" & i).Value = "CD" And Range("L" & i).Value = "2" Then
        Range(subConfig & i).Value = "D"
    ElseIf Range("K" & i).Value = "CD" And Range("L" & i).Value = "3" Or Range("L" & i).Value = "4" Then
        Range(subConfig & i).Value = "H"
    ElseIf Range("K" & i).Value = "CD" And Range("L" & i).Value = "5" Then
        Range(subConfig & i).Value = "G"
    ElseIf Range("K" & i).Value = "CD" And Range("L" & i).Value = "6" Or Range("L" & i) = "7" Or Range("L" & i) = "8" Then
        Range(subConfig & i).Value = "R"
    ElseIf Range("K" & i).Value = "CD" And Range("L" & i).Value = "9" Or Range("L" & i) = "10" Or Range("L" & i) = "11" Or Range("L" & i) = "12" Then
        Range(subConfig & i).Value = "T"
    End If
Next 'i
End Sub