What kind of game is it? Are you using user defined data types? It's pretty easy to do what you want if you are... a pain in the butt if you're not. You'll have to post some code or a link to the program.
Look up the syntax for the WRITE and INPUT # commands. They are ideal for a save game (unless it really matters if some variables can be changed. WRITE saves files in plain text, making them easy to change.)
I just happened to have run across a some tutorials explaining how to work with files: http://fbtk.net/phpBB2/articles.php?cat=1 (you'll want either the sequential files one or the binary files one)
I hope that helps!
Daniel "Theophage" Clark
theophage (at) geocities (dot) com
"God used to be my co-pilot, but our plane crashed in the mountains and I had to eat Him..."