Not from my knowledge. The proces start determines if the target is an executable. If not tryes to search for the default program associated with the extension and launches it like if you double click on the file.
If you want to interact with Excel, you'll need to use the Excel interop object model.
There have been several postings on this forum relating to accessing Excel spreadsheets from within VB. For example, I recently posted the following code which returns an array containg the names of all worksheets in a given workbook.
Private Function GetWorkSheetNames(ByVal ExcelFile As String) As String()
Dim names As String = ""
Dim xls As New Excel.Application
For Each sheet As Excel.Worksheet In xls.ActiveWorkbook.Worksheets
names = names & vbCr & sheet.Name