Well here is what I have found regarding using the 'filename' in calculated
columns. If anyone can correct my thinking, please do. I personally hate
this issue, it is a very limiting thing.

It seems to me that the construction of calculated  columns in a view works
only on 'columns' in the list (i.e. like "title" and not other read only
columns or calculated columns etc.

I figured out how to create new columns based on the schema and onet files,
but it seemed that no matter what I could do, unless the column  was based on
a "column" associated with the list, I couldnt use it.