Dynamically update app.config file using WiX

I have an msi built using WiX. Part of the installer collects some settings that will be entered into the app.config file of the installed app.

Now it works fine if I define <util:XmlFile ... for each setting that is going to change in the wxs file.

Now my question is this: is there a way I c开发者_开发知识库an dynamically create this util:XmlFile tag (e.g. from a custom action) so that I don't have to hard code it in to the wxs for each setting the app.config to update.

How does it do the collection? Are you doing an AppSearch and populating properties? Can you just use the [PROPERTY] in your XmlFile element? Note [PROP] is the value of PROP in MSI speak.