Your variable fullLink is being generated dynamically. it should have an <a element at the beginning, before the href=.
The \" is a way of preventing the write to page process from incorrectly thinking that the " is the end of the string started at "href=.
The +this.link+ is a way of filling in the correct href link detail from the information stored in the page object model before the page write. It should look something like "http://www.mySite.com".
The return false; suggests that the normal behaviour of the first href is being prevented. It all looks a bit of a mess, but its hard to tell untill the missing info is made available.
A Regular Expression is a method of finding if specific patterns occur in a string. For instance, checking the input format of an email address to make sure it conforms to the standard.