ahearn,

No, there is no way to do this if you are just opening the query
datasheet, apart from the way you are doing it.

However, in Access, Queries and Query Datasheets are generally regarded
as not suitable for human consumption.  They are usually attended to in
the design phase of the database, but should not really be directly used
for "production" data processes.  You should really be using a Form to
see the data returned by your query, by making the query as the Record
Source of the form.  In this case, you can put a Command Button on the
form, with a macro or VBA procedure, which will do what you want.  Just
make a simple macro with the Requery action, nothing entered in its
Control Name argument, and then assign this macro on the On Click event
property of the button, and every time you click the buttton the
parameter prompt will pop up.