VBA Excel - Mantaining Public Variables With Button Press - excel

Question

I'm trying to Create a document that has a bunch o constant strings.
I've declared then Public in a Module like this:
Public Abc As String
In "ThisWorkbook" I run the following code to initialize de variable
Private Sub Workbook_Open()
Abc = "C5"
End Sub
I have Buttons coded to change some values like:
If Range(Abc) = "" Then
Range(Abc) = 1
Else
Range(Abc) = Range(Abc) + 1
End If
When I run a button with this code:
Sub BotaoNovoDia()
i = 3
While i <= 33
If Cells(i, 11) = "" Then
Cells(i, 11) = Range(Apresentacao)
Cells(i, 12) = Range(Aceitacao)
Cells(i, 13) = Range(Aceitou)
Cells(i, 31) = Range("D41")
Cells(i, 11).Interior.Color = Range(Apresentacao).Interior.Color
Cells(i, 12).Interior.Color = Range(Aceitacao).Interior.Color
If Range("K34") < 0.65 Then
Range("K34").Interior.Color = vbRed
Else
Range("K34").Interior.Color = vbGreen
End If
If Range("L34") < 0.45 Then
Range("L34").Interior.Color = vbRed
Else
Range("L34").Interior.Color = vbGreen
End If
Range(Aceitou) = 0
Range(Rejeitou) = 0
Range(NaoApres) = 0
End
Else
i = i + 1
End If
Wend
End Sub
And i try to run the first button again I get and error saying: "Run-Time error '1004': Method 'Range' of object '_Global' failed"
the debug button takes me to the fisrt line that tries to access to the public variables value. What can i do to mantain the values in the Public variables?

Answer 1

When you call End (By itself, not as part of End If, etc) you clear your Globals.
Don't use End.

Answer 2

Using a named range is a great idea; but there's no reason why your public declaration shouldn't work - except for that pesky End statement. (I missed that first read through...)
However, your scope isn't clear in each of your functions, e.g. which worksheet is the Range referring to, so if one function works on another worksheet, pushing the button that fires "Change" could refer to a different place that doesn't like that reference.
e.g. your ranges should be something like SomeWorkbook.TheWorksheet.Range(<range>) and when you're changing the cell value, you should use .Value to ensure there's no ambiguity - you'll know from searching through here that error 1004 is the least descriptive error code...