If you have stored information within a Form field, you could pull each field according to its name (title of the field) and add it to a letter template within Daylite.
To edit an existing Letter Template, or to create a new one, go to the Daylite Preferences; Daylite-> Preferences-> Letter Templates-> and either double click on an existing template, or click the plus sign to create a new one.
To add information from a form field to your Letter Template, copy this text and paste it onto your template. Replace the "NameOfFormFieldHere" with the name of the field you want to pull from (exact match)
To send a letter template using information from the Form, rather then selecting the person and then triggering a letter template, select the form that is linked to the person, this way Daylite knows to look at that form.
Select the form and from the Edit Menu > select Merge > Write Letter in Daylite. Now you can select the letter template you setup, and choose the action.