Applying formula to filtered selection

Hello all,

I have the following question. I have a large data sheet with different manufactures and for certain parts of the manufactures I want to create a document with the following formula:

="MANU"&", "&"IRN"&", "&"COMP ID"&", "&[@[Part ID]]&".pdf"

When I apply this formula it automaticaly applies it to a large part of the sheet although I only want to apply it to the single cell. Or even better, to all the cell's with with a certain filter applied(like a certain company or a certain module I am working on).

Can anybody please explain to me how this works. So why does the formula applies itself to almost all of the rows of the table and is it possible to apply it only to the filtered columns?

Thank you very much in advance for your help.

Regards,

Milan