Date Reference Proxy fields

What I am trying to achieve?

I have 2 tables.

Expense Table which has a field for Expense Date (of type Date)
We are managing our expenses by the fiscal calendar. I have a separate table (Fiscal date table) that maps the cal date to the fiscal month/quarter/year.

On the Expense table form, when I select the expense date I want to be able to see fiscal month/quarter associated with it.

I cannot directly use the calendar date(from the Fiscal date table) on the form because that shows up as proxy field and doesn't open up in a calendar format.

Any suggestions ??

Appreciate the help.