I am researching a way to transfer a Max/MSP patch onto a circuit board
One is software. The other is hardware. Two entirely different things.
As Max/MSP is based on C++ I am hoping there is a way to convert the max patch to this source code and write it to the chip on the Arduino.
Well, that's a different story. But, since the Arduino is directly concerned with reading/writing I/O and serial data, and Max/MSP is concerned with something entirely different, there is not going to be any "universal translator".
On the other hand, if the Max/MSP patch is directly concerned with communicating with a serial port, for the purpose of commanding an Arduino, it MIGHT be possible to perform the same functionality without the need for Max/MSP to send instructions.
Without seeing the particular code in question, though, all we can do is wish you luck.