How to obtain a one-value share in Shamir's secret sharing
Well, Shamir Secret Sharing is done using a field $GF(p^k)$, for some prime $p$ and some integer $k$.  A share consists of two integers $(x, y)$, where $0 \le x, y &lt; p^k$.

So, the obvious way to express a single share $(x, y)$ as a single value would be to use the value $x p^k + y$ (using integer arithmetic, not field operations); each potential share would map to a distinct value, and during reconstruction, each value can easily be mapped by to the $(x, y)$ format.

Yes, this is just another way of doing concatination; you might find this somewhat more elegant.