You might not be able to. I thought that Application.SetOption might help but
it doesn't.
http://office.microsoft.com/en-us/assistance/HP051876091033.aspx
In part: If you followed the steps in either of the previous sections, you
left the Search Fields As Formatted check box selected as you searched the
Customers column of the Orders table. If you clear that check box and run the
find operation on the same data, the operation does not find any records.
Why? Because the data has an input mask applied.
So follow this rule of thumb: When the Search Fields As Formatted check box
is selected, leave the check box alone.
At times, it may seem like the Search Fields As Formatted check box is
selected for no apparent reason. For example, if you open the Orders table in
Design view and you select the CustomerID field (the field that contains the
customer data), you don't see a format or input mask listed on the General
tab. But if you click the Lookup tab (while in Design view), you see that the
CustomerID field uses a query to retrieve data from the Customers table. If
you open the Customers table in Design view, you see that the source field
(also named CustomerID) has a value in the Input Mask box applied: >LLLLL.
That input mask is the reason the Search Fields As Formatted check box is
selected.