How to call TV from snippet?

Let say if I have a TV call "HelloMarquee" and a snippet call "HelloSnippet" and a document call "Hello" so in the document I sould put in [[HelloSnippet]] but how do I tie the "HelloMarquee" with "HelloSnippet"

Is it possible to do that?

Thanks

...
$out= "[*HelloMarquee*]";
...
return $out;

So the TV is return a stream of text and can be assign into a variable in a snippet and therefore snippet can use it just like any variables.