Try the attached package. It is a package built using the Builder tab on MSP Console. I used the Persistent REG Install package builder template to create it

The most likely reason you are getting a -841 error on your install command is because merge.exe does not exist in \Windows or because the merge.exe that is in \Windows is not the program you think it is. Some MCD devices include a utility called merge.exe pre-loaded and some do not.  No MCD devices include the AirBEAM version of merge.exe pre-loaded.  If you know that your device includes a version of merge.exe, then you could build a package that assumes it is present and uses it.  But you would have to find out and use the proper calling seqence for that utility (which DOES NOT use -q and -r). To provide consistent operation on any device, we generally load the AirBEAM version of merge.exe (the one that takes the -q -r parameters) as part of any package that needs to merge a .REG file.  We usually have the package load the utility as abmerge.exe to avoid conflicting with or overwriting the merge.exe that may or may not be pre-loaded into the device.  Then we can be sure the version we want to call is present in the device and that the package will work no matter what. The Persistent REG file template for the integrated Package Builder tab of the MSP Console UI (which Vikranth used to build his package) is designed to do the above automatically.  So, it will build a package that has the utility in it, will place your .REG file into \Application (where it will automatically be re-merged on a cold/clean reboot), and will call the loaded abmerge.exe utility for the .REG file with the proper command line arguments.

Also note that changing the Registry is NOT guaranteed to make any Settings take effect immediately.  It depends on the OS and the type of Setting you are configuring whether it will or not.  Many OS-related Settigns are read from the Registry on boot and will not be read again until the next reboot.  Others can be read dynamically if some event is signalled AFTER the Registry is updated.  Others may be perioidically read from the Registry or read from the Registry on-demand.  So, if you find that the Regional Settings you are merging into the Registry are not fully taking effect, a warm boot may be required AFTER the .REG file is merged.