I just watched the guy do my pool and he had the same setup.
What you need to do is order a replacement cap for the filter pump, (The clear plastic thing that you can look into to see if the strainer basket on the pump). Do google on the pump manufacturer and ask them where you can get that piece. It should come with a gasket. The pool store may even have one... While at the pool store, pick up a straight hose adapter. This fitting is what you would buy to replace a fitting for vacuuming. You can probably get that piece at the plumbing store.... You will also need a nut to fit the threaded portion on the fitting. Then you drill a hole in the clear plastic piece that the fitting will fit in. Then you use silicone sealant bead around the hole. Insert the fitting, thread on the nut and your're done. My closer told me that you can use a leaf blower to blow out the line. I'll have to make up a fitting to go from the blower to the filter...
A picture of the installed cap and fitting is here