You can use store_ref(b, c)
: https://docs.ton.org/develop/func/stdlib/#store_ref
It stores a reference to cell c into builder b. You should be able to use references to store any amount of cells, but for a single cell there can only be 4 refs. This still allows for a tree of cells to read from.
https://answers.ton.org/question/1539108146436378624/does-store-slice-act-like-store-ref