This function is used only in hidden contents (map editor of Alice in
Kaeru nyo Land and unit editor of Daiakuji).
This implementation just calls menu_inputnumber(), while the original
ShPort.DLL shows a listbox.
We only support a fixed set of modules, so dynamic linking isn't really
necessary. This paves the way for running System3.9 games on more
platforms.
NIGHTDLL is temporarily disabled, because many symbols conflict with the
SACT module.
kichikuou