int str_num_array[] = { STR_xxx, ... };

#define NUMBER_OF_XXX (sizeof(str_num_array) / sizeof(int))

初始化：
void init__Msg_xxx(void)
{
int i;

for ( i = 0; i < NUMBER_OF_XXX; i++ )
Msg_xxx[i].f3=_GETSTR(str_num_array[i]);

}