This function can be used to dynamically populate structure members as they are accessed.
Syntax
miva_struct_member_callback( struct var, function, data var )
Return Value: Empty
struct = The structure that had the member accessed
function = a string containing the callback function name that will be triggered when a member does not exist in the structure (if the callback function is empty, the callback will be disabled)
data = The data that will be passed to the callback function