Could it be possible to automate filter a column base on the File naming convetion

Hi,

I would like to create a VS2010 program so it can fill in a Column of a document library with Period. All files saved to this library MUST have the naming convention (e.g Inventory_2012_MR_A.xls, Inventory_2012_MR_B.doc ... etc) and I have a column on that library will be stored the extracted value 2012 so later on we can filter this to obtain all documents in 2012..

Once the document is published, it will trigger the event to extract the period... 

Please help on how to do this...

Thanks