All you need is some stock plastic tubing to solve this dilemma.
What you want to do is basically extend the hose from the pump dispenser so that it can reach a large bottle of soap that can sit on the floor of the cabinet!
You can pick up stock tubing at any home improvement center. You need a piece that is long enough to extend from the base of the dispenser to the bottom of the soap bottle.
Make sure it will bends a little onto the bottom of the soap bottle so it can reach all of the soap.
If the tubing is a little tight when you're trying to fit it on the dispenser, soak the end in some hot water for a minute. It will make the plastic pliable enough to get it where you need it and as it cools it will ensure a tight seal to your pump.
Once you've got the pump and dispenser tethered to each other with the tubing, push the pump several times to prime the tubing. Once your soap has reached the top you're all set.
An ah-ha project that solved a frustrating dilemma. I'm Mrs. Fixit and it's just that simple!