New method I only have 1 .rm so I used the .wav I made from it & another .wav I had.It might have worked with 2 .rm's But I didn't test it.
USE MediaCoder Audio,put the files in.
Select Join under Task mode.
Resample at some rate I used 48000 this worked but original didn't work since the .wav's had different rates.
Highlght all files .Start transcode.
This worked for me.