I need a relatively simple (I think - it's getting more complicated by
the minute ;) ) VBS script that does the following:

1. Queries machine name

2. Queries
[HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Windows Messaging Subsystem\Profiles\MS Exchange
Settings\0a0d020000000000c000000000000046]

Reads the data stored in value "001e0324" (the data will be in the
form pathname\file)

3. Queries filesize of the returned data

4. And then writes all of the queried information to CSV.  Such as:

Machinename,filename,sizeinbytes
BLAH123,c:\documents and settings\blah\blah\filename.pst,1234567

Gotchas:
#1:
It's possible the value 001e0324 won't exist.  If it doesn't
"NONE,NONE" should be listed for filename,sizeinbytes

#2:
In fact, it's possible the key won't exist - what do I mean by that?

Well, while the registry value is usually in this "generic" form:
[HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Windows Messaging Subsystem\Profiles\MS Exchange
Settings\0a0d020000000000c000000000000046]

It can also be in this user specific form:
[HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Windows Messaging Subsystem\Profiles\Firstname
Lastname\0a0d020000000000c000000000000046]

Therefore, I suspect what will need to happen is:
1. Enumerate:
[HKEY_CURRENT_USER\Software\Microsoft\Windows
NT\CurrentVersion\Windows Messaging Subsystem\Profiles\]

2. List value(s?) there (which would either be "MS Exchange Settings"
OR "Firstname Lastname" OR some other variation I haven't seen yet) -
but I suspect there will only be one (i.e. there won't be "MS Exchange
Settings" AND a "Firstname Lastname")

3. Query the \0a0d020000000000c000000000000046 below the appropriate value.

Take a look at http://www.robvanderwoude.com/index.html and see if it
helps. Specifically, the reg.exe page
http://www.robvanderwoude.com/ntregquery.html ...

(except... reg.exe won't parse remote HKCU, just HKU and HKLM...)

I like awk, particularly, so I'd parse the result... 

OTOH, you could put a batch script to have the individual computers
make this report for you....

Simply drop a .bat in the allusersdirectory\program files\startup of
each machine and have it do something like
regedit /e \\path\to\collectdir\%computername%.txt HKEY_LOCAL_MACHINE\blah\blah

then grep the information from *.txt to a file ....

so much easier with awk and grep...