Sean,
Are we talking about fields or named variables?
Terminology changes between applications. For instance, 'range' means
something different between Excel and Word, so you must specify which
application you are addressing with a syntax word.

To see example of a word editor 'fields':
Open word and use menu Insert/Field. A dialog box will show you all the
pre-built fields and their options. Recording a macro while inserting a
field will help produce VBA code, if needed. VBA code using the environ()
function can access Windows OS environmental variables ( for getting things
like login user, who may not be the same as using a field that returns
document author's name ).