Alright, so you have a directory like C:\Incoming\0323 (representing today's date) and you want to make a directory like /Today that automatically points to that directory (which happens to change every day)... well here's how you do it:
You can simply add this line to your virtual file system (.vfs) file:

c:\incoming\%y|/Today|username|group|755|r|0|0|0|0|0|0|0|0|0|

Remember the VFS format! The "|" (pipe) is a separator. C:\incoming\%y points to that dated directory you made in C:\incoming (study up on your variables). /Today is the directory as your users will see it. The rest of the line designates the owner and permissions.

Things to note:

#1. You must have the physical directory c:\incoming\0323 (or whatever today's date is) in present.

#2. You must also create an empty directory, /Today, under your ftp's root (/) directory (ex: c:\FtpdRoot\Today, if your ftp's root directory is c:\FtpdRoot)