Question : call shell failing

Procedure used to work when MS Excel 2003 installed. It has been uninstalled. Now Excel 2007.
Now when execute Call Shell(stAppName, 1) error is : 'File not found'      
    Dim stAppName As String
    DoCmd.TransferSpreadsheet acExport, acSpreadsheetTypeExcel9, "q_enrollment_dif_2email", _
        "C:\Databases\ESP\Email\enrollment_dif_2email.xls", -1
    stAppName = "Excel.exe C:\Databases\ESP\Email\enrollment_dif_2email.xls"
    Call Shell(stAppName, 1)

Suggestions please.

Answer : call shell failing

stAppName = "Excel.exe

has the location of Excel.exe changed?  If so, you may want to specify the full path to it.