Put them in an XML file and import them in your ACP

To get an example of how to do it, either dload the HTL or just use this as a...well template
PHP Code:
<?xml version="1.0" encoding="ISO-8859-1"?>
<style name="Custom" vbversion="3.0.3" type="custom">
<templategroup name="This normally doesnt have to be changed.">
<template name="yourtemplatename" templatetype="template" date="1089120180" username="somespam" version="3.0.3">
<![CDATA[
All your template coding are belong to us!
]]>
</template>
</templategroup>
</style>