I thought of generalizing it myself :)

>Steve,
>
>I think this would solution would work
>For this puzzle
>NUMBER_TO_REACH = 100
>MAX_CHOICE = 10
>
>Iif( Mod(NUMBER_TO_REACH,1000) = 0, 1, Mod(Mod(NUMBER_TO_REACH, 1000 ),MAX_CHOICE + 1 ) )
>