[AccessD] Function with Operators and Conditions

Hey All
Is it possible to embed an operator or condition in a function that is 
used as criteria in the query grid.
I am sure I have solved this problem before, blame it on old age.
What I want to do is change the criteria on the fly.
Equal to   FndMyDate(=  Date variable)
Less Than FndMyDate(<Date variable)
Show all    FndMyDate(Like *)