How do I select parts of a string with javascript and add html tag to that?

I Have a Paragraph and want to select the first line that ends with a ! or . or ? and give it a header tag.

Than at the end of the paragraph I want to select the words that start with a # and make them disappear.

<p>
  Lorem ipsum!
  Dolor sit amet, consectetuer adipiscing elit. Aenean 
  commodo ligula eget dolor. Aenean massa. Cum sociis natoque 
  penatibus et magnis dis parturient montes, nascetur ridiculus 
  mus. Donec quam felis. 
  #sociis #natoque #penatibus #magnis
</p>

Should be:

<p>
  <h1>Lorem ipsum!</h1>
  Dolor sit amet, consectetuer adipiscing elit. Aenean 
  commodo ligula eget dolor. Aenean massa. Cum sociis natoque 
  penatibus et magnis dis parturient montes, nascetur ridiculus 
  mus. Donec quam felis. 
</p>

This is what I have found so far: http://ift.tt/1CG1D93