The best way to do this is to create a simple userform
http://www.gmayor.com/Userform.htm which collects the variable data and inserts it into the required places in the document using bookmarked locations. You will find a handy function for filling bookmarks with values from the userform at
http://www.gmayor.com/word_vba_examples.htm
Variable data can be read from a data source (or sources), ideally Excel worksheet(s), or it can be typed into a text field. The examples in the first link used typed data. For more on filling list boxes from external data see
http://www.gmayor.com/Userform_ComboBox.html