Condition to pick the file from File adapter

Hi friends,

I have a requirement where i need to pick the file with few validations on the file name..

yyyy29042009_MAT09000500.csv

this is the file name format in the ftp server which i am having..

now i need to pick the file with date in the file name equal to current date and the highest number after MAT...

if a ftp has many files with same date stamp but i have to pick the latest one on that particular date..

And one more is once if it picked for one day it should not pick again for the same day..

rite now i am using this logic..

i used file name as yyyy.CSV

and archived the files to new folder..

Regards

Vijay