How can I change the default UI language when installing a patch/update?

The problem is that the patch takes the initial language in which the setup to be patched was installed and not the current system language (defined in Reginal Settings/Advanced Options). I wonder if there is a property or switch that I can pass to a msp file to change its UI language.

Example:

1. I created 'setup_v00.exe' (english and french) and a patch 'update_v00_v01.exe' (english and french);

2. with system language = english, 'setup_v00.exe' installs in english;

3. change system language in french;

4. with system language = french, 'update_v00_v01.exe' still installs in english but I want it to install with a french interface;