The List command inserts an element in a list at a specified location.

$\mathrm{with}\left(\mathrm{MmaTranslator}\left[\mathrm{Mma}\right]\right)\:$

$\mathrm{Insert}\left(\left[2\,4\,8\,10\right]\,6\,\left[3\right]\right)$

$\left[2\,4\,6\,8\,10\right]$

$\mathrm{with}\left(\mathrm{MmaTranslator}\right)\:$

$\mathrm{FromMma}\left(\mathrm{`Insert[\{2,\; 4,\; 6,\; 10\},\; 6,\; [3]]`}\,\mathrm{evaluate}\right)$

$\left[2\,4\,6\,6\,10\right]$