If the window is custom, then copy trial_ui.h to trial_cui.h. (The ``cui'' stands for custom user interface!) Now edit trial_cui.h by putting an asterisk in from of any item name which will needs to be multiply generated. We will be making the item into an array of items. For example, if we want to have a whole list of varb_value items on the window:
typedef struct { Xv_opaque win; Xv_opaque pan; Xv_opaque button1; Xv_opaque setting1; Xv_opaque varb_value; } trial_win_objects;
becomes
typedef struct { Xv_opaque win; Xv_opaque pan; Xv_opaque button1; Xv_opaque setting1; Xv_opaque *varb_value; } trial_win_objects;