As I see it (?) the users on the peer network are all accessing the same
peer server for the data in the folders/drives:

F:\
F:\data
F:\DATA\Acquire Home Services
F:\DATA\Paradox
F:\DATA\WP9 App data"
C:\WINDOWS\Application Data\Corel\PerfectExpert\9\Custom WP...

If you create the share(s) for these folders on the peer server the
network users will map these locally to the drive letters as you want
them, (H,J,K...) either with the subst or net use command. The only
reason you would need to subst them on the peer server is if the peer
server is also being used for the same application ie

Exactly right!

I've written a number of tools for my office software and I want to use the
same tools on all the PCs. The PCs are all very different in configuration,
so I also need a consistent set of share points onto which the individual
PC's drives can be mapped. I want to end up with a set of identical share
points on each PC so that the same configuration data can be used for each
PC's office software.

Configuration then is straight forward, and is independent of the PC
hardeware setup, and if I modify a macro, it's immediately availble to all
the PCs.

; as a workstation also, and because it can't map the shares to itself.
You cannot share subst drives, so the other users will have to map to the
folder shares.

....yes, this is what I beginning to wonder.

I notice on my XP machine, there is a NET SHARE command. It's starting to
look as though I should have built the XP machine to be the "server".

Stephen