Hi Diann! It sounds like you will be heading to the
Fort Wilderness Campground Resort for your next Walt Disney World vacation! It is a place I call home for many weeks of the year as we bring our motor coach down for a few months. It is a unique and beautiful resort offering its guests many different ways to enjoy their time at Disney.
To add a request for a location you need to call the central reservation number, 407-934-7639 and have them add that request to your reservation profile. You can also call the resort at 407-824-2900. You must always realize that these are simply requests and while Disney will do whatever they can to satisfy your request it is not always possible.
When you are looking at Fort Wilderness you have to realize there are three different levels of loops to reserve: Premium, Preferred, and Full Hookup. There are several loops under each category with the Premium loops outnumbering the rest. If you don't have a favorite loop in mind then your request might be easier to meet since they will have more choices.
About ten days before your arrival I would also suggest you send a simple and quick Fax to the resort requesting again your desire to be close to a Comfort Station. The Fort Wilderness Fax number is: 407-824-3508. If there is a specific medical reason for this request please be sure to include that.
Have fun!