Automating our psftp get process

Hi Everyone,
We currently are using the get command from within our psftp
connection to do the following: 
      get filename.yyyymmdd    

eg. get
filename.20120413

Does anyone have any examples or suggestions on how we
could set the current date to the file name each day, so that we can grab the
latest file without having to manually change the date first?

Thanks,

Adam