Seeking help updating VBA script for generating all combinations using columns

[digitdash]

So i have a VBA script that I'm using to generate all possible combinations using 4 columns of data. The output is needing to be formatted a certain way as well. Currently this is what I have:

Option Explicit

Sub Sample()
    Dim i As Long, j As Long, k As Long, l As Long
    Dim CountComb As Long, lastrow As Long

    Range("G2").Value = Now

    Application.ScreenUpdating = False

    CountComb = 0: lastrow = 6

    For i = 1 To 15: For j = 1 To 23
    For k = 1 To 9: For l = 1 To 11
        Range("G" & lastrow).Value = "key=" & Range("A" & i).Value & "&details=" & _
                                     Range("B" & j).Value & "/" & _
                                     Range("C" & k).Value & "/" & _
                                     Range("D" & l).Value
        lastrow = lastrow + 1
        CountComb = CountComb + 1
    Next: Next
    Next: Next

    Range("G1").Value = CountComb
    Range("G3").Value = Now

    Application.ScreenUpdating = True
End Sub

It does indeed work to a certain extent, however the issues are that it only seems to return combinations of all 4 columns, when I'd like for it to return combinations using 1-3 columns as well. Essentially like this:

key=1&details=2
key=1&details=2/3
key=1&details=2/3/4
key=1&details=2/3/4/5

Also, I somehow was able to get 1/2/3 to work, however it keeps adding a / on the end if the combination uses less than all 4 columns which is messing up what I'm using it for. How would I go about generating the combinations without a trailing / ? Any help with this would be greatly appreciated, I've been stuck on it for hours. Thanks!

[JohnTopley]

This ??

xstr = "key=" & Range("A" & i).Value & "&details=" & _
                                     Range("B" & j).Value & "/" & _
                                     Range("C" & k).Value & "/" & _
                                     Range("D" & l).Value
        If Right(xstr, 1) = "/" Then Range("G" & lastrow).Value = Left(xstr, Len(xstr) - 1) _
        Else Range("G" & lastrow).Value = xstr