In order to match the string in between <h1> tags you will want to use the regex:
<h1>[a-zA-Z0-9]<\/h1>
the \/ before the last h1 is an escaped / ( \ / without the space, not a V)
This regex will match any string of letters, capital letters, and/or numbers inbetween the <h1> </h1> tags.
I am more use to C and Java programming and Bash and Perl scripting than Javascript, but I believe that you can use the string.match(<regex>) function to return the string that matches the pattern you are looking for. For this, you will need a variable that contains the contents of the file in which you are parsing for the html tags. So, have a variable, say var file1, that contains the contents of the file and a second variable to hold the matched pattern. If you are expecting multiple variables you might want to use an array to store them. So, the code would look like this:
var file1=new String(<file contents>);
var pattern=new RegExp(<h1>[a-zA-Z0-9]<\/h1>, g);
var string1=file1.match(pattern);
var arrayOfStrings=string1.split(,);
You will want to use the string.split(< delimiter >) function because the string.match(<regex>) function will return comma-delimited string of all matches and split will break them up and put each string in it's own element in an array.
I believe this will do what you are looking for, but I have not tested it. If anyone else has any other suggestions, please feel free to correct any mistakes I have posted here.