How to use Instaup2date and installer choices…

How do you use instaup2date to place an InstallerChoices.xml file with the alias/symlink in a folder? I have some custom InstallerChoices.xml files that go with some of the packages that I use for different builds. How do I ensure when creating a catalog file that the right InstallerChoices.xml file gets placed were it should. I am currently doing it manually at the beginning of the build.