how is a weekly FULL bkup scheduled?

[MC Matt Cooper (2838)]

Hello,
        I am trying to figure out how to set up a scheduled job that will do
a Full backup every weekend of a client.  I will be running daily
incrementals and will have the POLICY set to keep 4 copies of the backup.  I
just don't see how to get the client to do a full backup after the intial
has been done.   What am I missing?
Matt