No, of course MAX will not see a GPIB resource since you do not have an actual GPIB controller.
It has been a very long time since I have used the GPIB-RS232 converter and when I did I wrote my own driver, but since it uses VISA, you should be able to modify the driver and incorporate the write and read functions from the link. I would replace all of the VISA Writes with the Write ConvBox and all of the VISA Reads with Read ConvBox.You would also need a new input for each function in order to provide the GPIB address.
