Creating a query to select 1 of 3 tables

I have an Access database that uses three primary tables that are linked to
an SQL database. The tables have millions of records and cannot be be joined
using a union query due to the inefficiency of running queries across the
network. I'm needing to create a query that will call the correct table when
criteria is selected in a form using a drop down menu. I'm thinking an "if
else" statement may work but not sure if this can be used in Access. An
example could be:

If [Forms]![Pick]![segment] = "WIS"
EXEC [WIS query]
ELSE
If [Forms]![Pick]![segment] = "Count"
EXEC [Count query]
ELSE
If [Forms]![Pick]![segment] = "Summer"
EXEC [Summer query]
END

Can an "if else" statement be used in Access?

Another approach I've tried was creating created a macro to select the
appropriate table/query. I've successfully done this but do not know how to
use the results of a macro in a new query. Is this possible? Any help would
be appreciated.