<% MkSheet Server.MapPath("/file.xls") %>

source code:
<%
Private Sub MkSheet(ByVal pathname)
    Dim objXls, objBook, objFSO
    Set objFSO = Server.CreateObject("Scripting.FileSystemObject")
    If objFSO.FileExists( pathname ) Then
        Set objFSO = Nothing
        Err.Raise 5150, "MkSheet Statement", _
            "File Already Exists! MkSheet " & _
            "can only create sheets."
        Exit Sub
    End If
    Set objFSO = Nothing
    On Error Resume Next
    Set objXls = CreateObject("Excel.Application")
    If Err Then
        Err.Clear
        On Error GoTo 0
        Err.Raise 5150, "MkSheet Statement", _
            "Microsoft Excel Is Not Installed " & _
            "On This Server!"
        Exit Sub
    End If
    Set objBook = objXls.Workbooks.Add
    objBook.SaveAs( pathname )
    Set objBook = Nothing
    objXls.Quit
    Set objXls = Nothing
    On Error GoTo 0
End Sub
%>