Here's a way, to get you started
Try this code to get you started. Of course you would need to insert your "perform the task" code, and modify it for your actual file name and path. I put in a bunch of notes so you can see why each line does what it does.
Hope this helps:
Sub OpenFiles()
'Error code so you don't have to worry
'whether the DailyFile is open or closed
'at the time you run your macro, this way
On Error Resume Next
Windows("DailyFileName.xls").Activate
On Error GoTo 0
ChDir "C:\Your\File\Path"
Workbooks.Open Filename:="C:\Your\File\Path\DailyFileName.xls"
'YOUR MACRO GOES HERE
'Then when you are done, save and close the DailyFile
'Note, activate it first, in case your macro's
'last step involves a different workbook:
Windows("DailyFileName.xls").Activate
ActiveWorkbook.Save
ActiveWorkbook.Close
End Sub
HTH
Tom Urtis