It sounds like what you want is something to concentrate light, not necessarily magnify anything.
For the former, you can simply use multiple mirrors. You can use normal flat mirrors (for example, by having a bunch of pairs of mirrors that all reflect incident sunlight toward a specific point), but focusing light is easier if you also have convex mirrors (with focal points of one or more meters).
I won't give you a design, because there are a literally infinite number that'd work well, and because you'd need a diagram to implement it (and I'm terrible at diagrams). But this is the general principle.