If I understand correctly… This could help? 
This will add this html after logo <a href="/" class="after-logo">After logo text</a>
Header
<script type="text/discourse-plugin" version="0.8">
api.decorateWidget('home-logo:after', helper => {
return helper.h('a.after-logo', {
href:'/',
text: 'After logo text'
});
});
</script>