Message "parametervalue.xlsx could not be found. Check spelling..."

I have 2 issues.

I am starting Excel (2010) from within another application, sending the name of the spreadsheet to open (somename.xls) and a parameter (which contains a comma separated list of numbers ) to use to filter the spreadsheet once it's open. I have VBA code that turns the list into an array and uses that as the criteria for filtering. That works.

But once the spread sheet opens and displays my filtered list of rows, I receive a message similar to this:

11274,14075.xlsx could not be found. Check the spelling of the name and verify that the file location is correct. If you are trying to open the file from your list of most recently.....

11274,14075 is actually the information in the parameter, not the name of the spreadsheet.

And, I'm not even trying to open an xlsx spreadsheet, rather an xls spreadsheet.

Then when I close the spreadsheet, Excel asks me if I want to save it. It's a read-only file, so I don't want the user to save it, I'd like to suppress the save message.

I've seen some reference to setting registry values, re-registering Excel, changing options on the File type Open statement, and have tried all of those things.

I only started getting this message when I open a spreadsheet programatically like this. If I double-click on it directly, it opens with no error.
This is my execution string:

C:\Program Files\Microsoft Office\Office14\excel.exe O:\SegmentHistory2.xls /e/r/ 11274,14075

Any suggestions as to how to get rid of the first message, and how to suppress the Save dialog?

I want to open the spreadsheet and use the parameter value to filter the rows. That part is working. I'd like to get rid of the message that is looking for a spreadsheet that doesn't exist and I'm not trying to open.

I don't have WorkBooks.Open anywhere in my VBA code.

I'm opening Excel from another application. That application is executing:

"C:\Program Files\Microsoft Office\Office14\excel.exe O:\SegmentHistory2.xls /e/r/ 11274,14075"

In the Excel documentation, it says you can open Excel with switches and parameters. The /e/r are the switches I want to use (no startup screen, read only) the rest, " / 11274,14075" is a parameter (comma separated list of numbers).

VBA code in the spreadsheet parses the command line parameters and uses that list to filter the records.

Why does it think I want to open a spreadsheet named "11274,14075.xlsx"?

Same result.

It's looking for an xlsx with the name being my parameter list. e.g. 12345,32145.xlsx

Does anyone else have any suggestions?