Excel 2007 :: Copy Data From Another Workbook?

I have two Workbooks

1. Main (where I have a button and I intent to write code and paste the data)

2. Data (where I have data to be copied)

My code so far

Code:
Sub copy()
Dim wbData As Workbook
Dim wbMain As Workbook
Set wbData = Workbooks.Open("path")
Set wbMain = Workbooks.Open("path")
wbData.Sheets(1).Range("A1:A5").copy
wbMain.Sheets(1).Range("A1:A5").PasteSpecial
wbData.Close
End Sub

In the above code the problem is that the file wbMain is already open and when I try to re-open it gives an error and program crashes and if I do not open the file then it gives me the error and says sub or function not defined as wbMain variable is not set.

Second problem:When an error is thrown or I close my files, I lose all the VBA code and module? strange ! how to save modules permanently? using Excel 2007