Email URL formula link text

I currently have a URL Formula button that opens the users email client and automatically fills in the relevant information (i.e.: To, subject and body). I have everything working and decided to put in links to a video and pdf since we can't natively attach them. However, I was wondering if there was a way to change the text of the link, similar to html aref.
I am also wondering how to link in another application since that is where our pdf file is stored.