Creating HTML Template with dynamic fields

Hi All,

I am setting up a workflow to send email notifications whenever an Incident is changed. I have a generic HTML template and the workflow works but I would like to know how I can include dynamic information in the body of the email, items such as ticket #, subject, etc..

For example, my email looks like this

#SOURCE# request about "#SUBJECT#" created on #CREATEDON# has been updated. This is for Ticket: #TICKETDI#

Now this was an HTML template given to me by someone else and I thought the # referred to variables that would be populated.

Any idea how I can create/edit my HTML template to include those pieces of information?

Thanks in advance.