Vba excel summary sheet required

I need vba code to extract(copy) data from multiple closed excel spreadsheets and consolidate the information on a summary workbook., they need to stay closed, I also need it to have a drop down box that the user select the month they want to view, as each spreadsheet will have the month in it name: eg staff-team1-January2018

Lastly they need to select to view just each team or all. (So another drop down)

I will supply more details on request.