Unique value on a click

Hello,
What I am trying to do is generate a unique value from 1 to 23 each time a user clicks on a button. I used this code for generating random numbers in a list

Sub Macro1()
    Dim iAdd As Integer
    Dim iLimit As Integer
    Dim iCheck As Integer
    Dim iRnd As Integer
    Dim UniqueNumbers As New Collection


    iLimit = 23

    For iAdd = 1 To iLimit

StartAgain:

        iRnd = Int((iLimit - 1 + 1) * Rnd + 1)

        On Error Resume Next
        UniqueNumbers.Add iRnd, CStr(iRnd)
        On Error GoTo 0

    Next iAdd

    If UniqueNumbers.Count < iLimit Then GoTo StartAgain

    For iCheck = 1 To iLimit

        ActiveSheet.Cells(iCheck, 1).Value = UniqueNumbers.Item(iCheck)

    Next iCheck

'
End Sub

Is it possible to make it so, that on every click to show a different number? (the purpose is to make a random drawing for each person for Christmas presents - person A makes present to person 20 for example, person B to person 14 and so on). The idea is to post the worksheet in google docs or something like that (not sure if google docs supports macros) and then whenever a person enters and clicks the button shows them the number they are supposed to give present to. Then the next person enters and shows them a different number. Is it possible at all?

This code creates a list (A1 to A23), but how do I make a code to choose each time the value of the corresponding cell and show it?
I mean on the first click it shows A1, on the second A2, on the 23rd A23, on the 24th shows a message or something...
Or maybe a different code that creates one value at a time, then store it and next time make a check if this value is already created?
I am sorry, I am a bit noob in this Thanks