No simple way that I know of.
Creating a drive letter (for a hard disk volume) is simple enough.
They are the Disk Signature and the offset (in bytes) to the beginning of the volume, see:
https://web.archive....t=0#entry130963
As well creating the {GUID] (the actual values in the {GUID} entry are the same.
Now creating the actual {GUID} might be a little tricky, the automatically generated one is a v1 "semi-random" GUID per RFC but it has to be seen if there is a validation of some kind or if it is just a "semi-random" string .
The UUID tool mentioned here:
https://www.forensic...586892/#6586892
should be able to produce a valid {GUID}:
http://soft.rubypdf....idgen-ossp-uuid
Please understand that the above is just "generic" a booting system should create those automatically, if it doesn't then there might be other and different problems outside and before the drive letter assignment, agan idf you don't somehow manage to repoort more exactlythe symptoms, it is difficul ot impossible to provide a diagnosis (let alone a cure).
Wonko