File naming with utl_file !

I have to append the date to a file generated with ult_file. Can someone give a few tips as to how to do this. The way I see it is to

select sysdate into var from dual;

var:= 26-SEP-05 (is now today's date)

How to get the filename as : filename26SEP05 or filename260905 ?

Thanks in advance !

:)

Something like:

filename := filename||to_char(sysdate, 'DDMMYY');