character picker determines secondary character picker character set

Hello,

I am trying to allow users of my program to edit a string.  The problem is I want to implement a unique symbol-based character set for this string, of over 250 symbols.  I've already created these symbols on a Font, and the Font is legible on the watchface, it looks great.  But because my character set is too large to make scrolling through each individual value efficient, I wish to implement a sub-group system, whereby in the first character factory, the user selects which sub-group they wish to select a character from, and in the second character picker the user can pick of a smaller list of 10-15 characters, and selecting the second character will add the character to the string.

I am thinking that maybe the first picker will change a global variable, and when the second picker is selected, it will determine it's characterset, or adjust the selectable index from subgroup A to subgroup B, which in my character set, might be simply 15 or 12 characters down the line.  The character subgroups are different sizes.

I am studying up on the character factory and the string picker examples, because I want the program to show the string while they are editing it.  

Any tips on how to implement this?  Thanks in advance!  I am working on a solution and will post here... thanks