Word - Accessing Excel from Word.

I’m using Office 2010, using VBA to access an Excel Spreadsheet to pick
up some values for my Word document’s Custom Control Listboxes. At the
moment I’m trying to make the Word code “bombproof”, using “On Error
Goto xxx”. I’ve had a look around to see if there’s a way to see if the
error occurred after I’ve opened the Spreadsheet, but before I’ve closed
it. Short of setting a User flag to say it’s open, I can’t see a way to
interrogate the Excel Workbook Object to see if it’s open. Does anyone
know a way?

Code snippets

Dim exWB                     As Excel.Workbook
Dim objExcel                 As New Excel.Application