Making Workbook Opened From Other Workbook Active

I have a workbook that is a formatted report that I need to insert data from a name variable "CSV" file. I have created a macro in this workbook that calls an "Open" dialog for CSV files that I can use to browse to and open the source file. The macro then is supposed to "select all" copy and close the workbook then make the original workbook active and paste the data starting at row 2. The macro "seems" to be working perfectly except when I do the open the macro then makes the original workbook active, selects all copies then wants to close the original workbook. How can I tell the macro that the csv file that I just opened should be the active workbook, baring in mind that the name won't be known before the time it's opened so I can't hardcode the "active. workbook (NAME) "route.