Thanks for clarifying in the comments.
I don't think you're looking to use merge tags, since you're just trying to change links in the template, not necessarily insert subscriber-specific info. So, the focus should just be making the links in the template editable by the sender, in the MailChimp editor. This way, the sender can create a campaign, select the template and edit the regions/links that you want to be editable.
To make a region editable, use the MailChimp template language. You can't make "a" tags themselves editable, but you can make a surrounding div or td editable.
<td mc:edit="links">
<a href="http://www.google.com">A link</a>
<a href="http://www.mailchimp.com">A link</a>
</td>
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