the best way to do this would be to create a new table, eg: tbl_criteria, and create a lookup field in this that you wish to be the criteria, for this example, we shall use months;
field months; Jan;Feb;Mar.. and so on
create a query, and in this query add in the table you wish to set the criteria for, add in the tbl_criteria too.
Create a link from the field in tbl_criteria (months) to the corresponding field in the other table (for this example it would have to be a month too)
Whatever month is then selected in your table, the query will filter results based on this and show them only.
Hope this helps,
sometimes simple is best.... and i'm just a simple fellow.