Here is another AppleScript version of a 
prior vba script. This one creates a back of the current
workbook. It copies the last saved version of the current workbook to 
a Backup subdirectory below the directory in which that file was saved.
It adds a counter (ie, .001) before the .xls(x) extension.
Rather than merging cells to center headers, I prefer to have text centered
across selection. This avoids problems with deleting and filling columns that
are cosed by merged cells. The following sets up a command to toggle centering
across columns.
Open up the AppleScript Editor, paste the following code and save it as
/Users/<your-username>/Documents/Microsoft User Data/Excel Script Menu
Items/AlignCentered\sca.scpt.  The \sca in the filename creates a
keyboard shortcut control-shift-a.
-- Align selected cells across selection
-- Copyright under GPL by Mark Grimes
-- Saving with '\sca' in the filename creates Shortcut: Crtl+Shift+a
tell application "Microsoft Excel"
    --activate
    tell range (get address selection) of active sheet
        if (get count columns) > 1 or (get count rows) > 1 then
            if (get horizontal alignment) is horizontal align center across selection then
                set horizontal alignment to horizontal align general
            else
                set horizontal alignment to horizontal align center across selection
            end if
        else
            if (get horizontal alignment) is horizontal align center then
                set horizontal alignment to horizontal align general
            else
                set horizontal alignment to horizontal align center
            end if
        end if
    end tell
end tell
      I recently switched to a Mac and really miss my auto color cells VBA script for Excel. After quite a bit of digging (and trial-and-error) I managed to recreate the functionality using AppleScript. It is pretty slow, but it works!
Just like the VBA version, this automatically color codes cells to help
identify inputs, formulas, etc. For example, cells that contain only numbers
are colored blue, all formulas black, references to other workbooks are green
and cells that include the =OFFSET() function (what I use for setting up
different scenarios) are rust.
Open up the AppleScript Editor, paste the following code and save it as
/Users/<your-username>/Documents/Microsoft User Data/Excel Script Menu
Items/AutoColorCells\scc.scpt.  The \scc in the filename creates a
keyboard shortcut control-shift-c.