This is still the same, but an augmented tool from the SDK for working with ".grp" format.
It was assumed that "gfbuild.exe " it is intended only for unpacking the archive "newgrp.grp".
There is no information or mention that this tool, in addition to unpacking files, can also pack them.
After a detailed study of the program's functionality in the code, it became clear how it works and how to correctly call the packing function.

Archive composition:
GFBuild - the folder where the files should be placed ready for packaging.
group.cfg - customized list that indicates exactly what will be packed.
gfbuild.exe - the program itself, you need to use the files below to make it work.
gfbuild_pack.bat - command that starts the process of packing files from the GFBuild folder into the newgrp file.grp considering group.cfg
gfbuild_unpack.bat - command that starts the process of unpacking files from the newgrp.grp file.
These files should be placed in the root folder of the game next to XENUS.EXE
Or vice versa, in order not to pollute the game folder and not make backups, add to the GRP Tool folder files listed above:
DX8RENDER.DLL, game.dll, VEDebug.dll, VELoader.dll, verender2.dll, VITAL.DLL

At the moment, group.cfg is configured so that it packs exactly what it unpacked from newgrp.grp.
The files that have been packed and unpacked have been tested for compliance in terms of quantity, weight and location.
Files unpacked using gfbuild_unpack.the bat is placed in the root folder next to gfbuild.exe
An approximate view of a possible list in the group.cfg file:
folder\*.*
folder\folder\*.*
folder\filename.format
folder\*.format
folder\filename.*
This means that only * can be specified in the list.* in this case, all files with any name and format from the folder will be added to the list.
You can specify only the desired file name or format, this is convenient if, for example, there are files that are being worked on or backup files.
The unpleasant point is that you cannot specify the following path in the list: folder\ or folder\*.* with existing subfolders.
If the full path to the file looks like this: folder\folder\folder\filename.format, and group.cfg specifies only folder\*.*,
then only all files from folder\ will be counted, everything contained in the subfolders will be excluded.

Google Drive[drive.google.com]
PlayGround[www.playground.ru]