Is there a way to filter file names using getopenfilename?

I would like to show only those .xls files starting with say "daily", not
all the .xls files.
I have tried
GetOpenFileName("Daily files (daily*.xls), daily*.xls", , , , True)
but this defaults to "All files (*.*)" in the "Files of type" box

If I use
GetOpenFileName("Daily files (*.xls), *.xls", , , , True)
then I get "Daily files (*.xls)" in the "Files of type" box BUT in the
list of
files the fliter hasn't been applied, ie all files in the folder are listed
for selection.

I am using Excel XP

Could someone help please?
Thanks
Chris