Look up field by date

[Porky]

Is it possible to create a feild that will look a field in a table related to the date recorded in that table? I want a form which will show'Date' 'cash in' (which I get from a query, also date dependant ie field one is payment date, with a criteria of enter todays date and field 2 is sum of cash. This info come from a different table) and 'petty cash out' and Todays 'till total' and, the hard bit, a field that will look up yesterdays 'till total' where 'till total' is the name of the field.