Vlookup and return value from a range of results?

Hi All,

Would appreciate any help with this dilema.

Reference Sheet
Contains the Customer ID, Membership Level and Membership Expiry

Working Sheet
Contains the Customer ID, Access Date and Calculation Column.

Required:
I am trying to return the Membership Level, for a given Customer, at a particular Access Date (row) from the Reference Sheet.

The expiry dates in the Reference Sheet is the upper limit. More than one line per customer means their Membership has changed and 31/12/9999 is current.

I hope this makes sense and please let me know if I need to provide more info.

Thanks again
Randy