As long as you connect through the server (i.e. using a host name, and
not trying to use Embedded mode), the fact your Firebird server is
32-bit and your office application is 64-bit is not important. The
important thing is that you need 1) the 64-bit Firebird client library
(fbclient.dll), 2) the 64-bit ODBC driver.
You can install the 64-bit Firebird client library using the 64-bit
Firebird server installer, and the 64-bit ODBC driver using the 64-bit
ODBC driver installer.
Mark