s-function and CAN_MESSAGE struct as input/output

Hi

I want to create an s-function (using s-funtion builder) that reads a new can message from the can fifo on my hardware and then store the message in the CAN_MESSAGECAN_MESSAGE struct that I can unpack with the existing can unpack block. Then I want to pack data with the existing can pack block and send this in another custom s-function. How can I make the s-function blocks input/output a CAN_MESSAGE when its not a bus nor a native type?

Kind regards Jonatan