batch file that will delete files by date

[beetleboy]

I am in need of some help writing a batch file that will delete files out of the specified folder. i have a folder named "backup" and within "backup" i have files that are named:
backup013106.bak
backup020106.bak
backup020206.bak
backup020306.bak
backup020406.bak
backup020506.bak
backup020606.bak
so i already have a batch file that copies the new backups into this folder and renames them by date but i would like to add to the file for it to keep only the 2 most recent backups and delete the older ones when ran. any ideas? thanks!

[dedub]

I'm not sure if it is possible with a batch. You may have to move to .vbs script to run a more powerfull *if-than* statement. I could be wrong though.