It is possible, as some companies that sell magnetic curtain rods will tell you, to glue these rods to the wall if you don't have metal to make the magnets effective. Just because this is possible, though, doesn't make it a good idea.
Basically, this is like replacing a burned out light bulb with a candle. Using glue to attach magnetic curtain rods negates every thing that the rods were designed to make easier; but if you're in a pinch, it can still do the job.
MagneRod Cafe Rod
Beautiful magnetic curtain rods for all steel doors.
The MAGNE ROD® Cafe rod projects 2" from the surface to allow your curtains to hang properly.
The bases of the rods vary in their magnetic strength. Those wishing to hang very heavy curtains should make absolutely sure that they are purchasing curtain rods with the strongest magnets. These will be both more expensive and harder to come by as well. Since magnetic curtain rods are a bit more expensive than traditional ones to begin with, price may be an issue if your curtains are especially heavy.
Magnetic rods are commonly used in slow, free flowing materials such as grain, food, spices, plastic and chemical fertilizer. The rods can be installed individually in one row or multiple rows. Standard spacing between the rods are 2-inch horizontally and vertically center-to-center. When multiple rows are needed for better separation, the rods should be staggered. Other center-to-center arrangements can be accomplished depending on product flow characteristics and flow rates. The rule of thumb for determining the center-to-center distance is that installations must not cause product bridging and must allow easy access for cleaning.