I went from the MX700 to the MX850, and you can use your existing software and the file from your MX700 directly into the MX850.

The only difference apart from colour is the MX850 has RF.

There is also a clone of the MX850 software available free.

[Link: files.remotecentral.com]

If the MX700 will not learn a code I doubt the MX850 will.