In a LyX document, you cannot insert the raw latex command
\setcounter{enumi}{3} (for example)
into any position where it will change the label of the first enumerated point
in a list.
If you insert it before the first point, which is outside the list environment,
it has no effect. If you insert it immediately at the beginning of the first
point, inside the list environment, it affects the labesl of the second and
subsequent points.
I believe in the exported LaTeX, it falls either outside the list environment,
or inside not only the list but also the item.
