Assuming your Homeworld RM installation is the same as mine, try:
C:\Program Files (x86)\Steam\steamapps\common\Homeworld\HomeworldRM\Bin\Release\HomeworldRM.exe" -overridebigfile -luatrace -traceHODs -nomovies -moddatapath ..\..\..\..\..\..\Users\Pouk\DropboxR\REARM_V2_Project\REARM_V2
If your Homeworld RM installation isn't the same as mine, let me know what it is.
(I hope I don't have to tell you this, but make sure
C:\Users\Pouk\DropboxR\REARM_V2_Project\REARM_V2\keeper.txt is a thing though...)