  Let $X$ be a complete simplicial toric variety over a finite field with a
split torus $T_X$. For any matrix $Q$, we are interested in the subgroup $Y_Q$
of $T_X$ parameterized by the columns of $Q$. We give an algorithm for
obtaining a basis for the unique lattice $L$ whose lattice ideal $I_L$ is
$I(Y_Q)$. We also give two direct algorithmic methods to compute the order of
$Y_Q$, which is the length of the corresponding code ${\cC}_{\aa,Y_Q}$. We
share procedures implementing them in \verb|Macaulay2|. Finally, we give a
lower bound for the minimum distance of ${\cC}_{\aa,Y_Q}$, taking advantage of
the parametric description of the subgroup $Y_Q$. As an application, we compute
the main parameters of the toric codes on Hirzebruch surfaces $\cl H_{\ell}$
generalizing the corresponding result given by Hansen.
