My understanding is that there are various formats to the different trip planners. The format that GS uses is not compatible with RM. That being said there are various programs on the web that allow you to convert from one to another. I tried it but since I am not computer literate I could not get it to work.
https://www.gps-data-team.com/convert.php
This is one that I found but as stated I could not figure it out, I am sure there are those of you that can. I hope this helps.