Apply Macro to multiple Workbooks at Once

[Prevostb]

I'm trying to apply this macro:

 Sub Macro8()
'
' Macro8 Macro
'
' Keyboard Shortcut: Option+Cmd+u
'
Dim WS As Worksheet

Set wsNew = Sheets.Add
wsNew.Name = "Summary"

    ActiveCell.FormulaR1C1 = "='31st'!R[9]C[1]"
    Range("A2").Select
    ActiveCell.FormulaR1C1 = "='30th'!R[8]C[1]"
    Range("A3").Select
    ActiveCell.FormulaR1C1 = "=-'29th'!R[7]C[1]"
    Range("A3").Select
    ActiveCell.FormulaR1C1 = "='29th'!R[7]C[1]"
    Range("A4").Select
    ActiveCell.FormulaR1C1 = "='28th'!R[6]C[1]"
    Range("A5").Select
    ActiveCell.FormulaR1C1 = "='27th'!R[5]C[1]"
    Range("A6").Select
    ActiveCell.FormulaR1C1 = "='26th'!R[4]C[1]"
    Range("A7").Select
    ActiveCell.FormulaR1C1 = "='25th'!R[3]C[1]"
    Range("A8").Select
    ActiveCell.FormulaR1C1 = "='24th'!R[2]C[1]"
    Range("A9").Select
    ActiveCell.FormulaR1C1 = "='23rd'!R[1]C[1]"
    Range("A10").Select
    ActiveCell.FormulaR1C1 = "='22nd'!RC[1]"
    Range("A11").Select
    ActiveCell.FormulaR1C1 = "='21st'!R[-1]C[1]"
    Range("A12").Select
    ActiveCell.FormulaR1C1 = "='20th'!R[-2]C[1]"
    Range("A13").Select
    ActiveCell.FormulaR1C1 = "='19th'!R[-3]C[1]"
    Range("A14").Select
    ActiveCell.FormulaR1C1 = "='18th'!R[-4]C[1]"
    Range("A15").Select
    ActiveCell.FormulaR1C1 = "='17th'!R[-5]C[1]"
    Range("A16").Select
    ActiveCell.FormulaR1C1 = "='16th'!R[-6]C[1]"
    Range("A17").Select
    ActiveCell.FormulaR1C1 = "='15th'!R[-7]C[1]"
    Range("A18").Select
    ActiveCell.FormulaR1C1 = "="
    Range("A18").Select
    ActiveCell.FormulaR1C1 = "='14th'!R[-8]C[1]"
    Range("A18").Select
    ActiveCell.FormulaR1C1 = "='13th'!R[-8]C[1]"
    Range("A19").Select
    ActiveCell.FormulaR1C1 = "='12th'!R[-9]C[1]"
    Range("A20").Select
    ActiveCell.FormulaR1C1 = "='11th'!R[-10]C[1]"
    Range("A21").Select
    ActiveCell.FormulaR1C1 = "='10th'!R[-11]C[1]"
    Range("A22").Select
    ActiveCell.FormulaR1C1 = "='9th'!R[-12]C[1]"
    Range("A23").Select
    ActiveCell.FormulaR1C1 = "='8th'!R[-13]C[1]"
    Range("A24").Select
    ActiveCell.FormulaR1C1 = "='7th'!R[-14]C[1]"
    Range("A25").Select
    ActiveCell.FormulaR1C1 = "='6th'!R[-15]C[1]"
    Range("A26").Select
    ActiveCell.FormulaR1C1 = "='5th'!R[-16]C[1]"
    Range("A27").Select
    ActiveCell.FormulaR1C1 = "='4th'!R[-17]C[1]"
    Range("A28").Select
    ActiveCell.FormulaR1C1 = "='3rd'!R[-18]C[1]"
    Range("A29").Select
    ActiveCell.FormulaR1C1 = "='2nd'!R[-19]C[1]"
    Range("A30").Select
    ActiveCell.FormulaR1C1 = "='1st'!R[-20]C[1]"
    Rows("18:18").Select
    Selection.Insert Shift:=xlDown, CopyOrigin:=xlFormatFromLeftOrAbove
    Range("A18").Select
    ActiveCell.FormulaR1C1 = "='14th'!R[-8]C[1]"
    Range("A18").Select
End Sub

To all multiple .xls files in this folder directory:
/Users/prevostb/Desktop/Hillsboro Club_MASTER /Daily Reports/2008 Daily report

If a prompt could be setup to select folder with .xls files in it - that would be ideal

I'm working on a Mac excel 2011 if that makes a difference.

Thanks.