After much deliberation we seem to have been able to capture the licence for Ultra Edit, without the need for the custom installer.

1) Extract MSI from EXE installer (simply run it and copy away from %temp%)

2) Create a Transform with ISSETUPDRIVEN=1

3) Install MSI with MST to ensure that works (note the custom font causes a few problems)

4) Launch product

5) Select your favourite MSI Packaging tool: MSI Studio, and run a capture

6) The file you're looking for is uedit32.spl and exists in the Application Data Folder (\IDMComp\UltraEdit\license)

7) I did pick up the following keys; these are likely to be unique to this environment:

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}]
@="wodFtpDLXCom Class"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}\InprocServer32]
@="C:\\Program Files\\IDM Computer Solutions\\UltraEdit\\wodFtpDLX.dll"
"InprocServer32"=hex(7):43,00,60,00,36,00,78,00,47,00,4e,00,58,00,3d,00,4f,00,\
40,00,61,00,62,00,7d,00,53,00,69,00,51,00,32,00,7e,00,38,00,50,00,43,00,6f,\
00,6d,00,6d,00,6f,00,6e,00,46,00,69,00,6c,00,65,00,73,00,3e,00,40,00,53,00,\
28,00,28,00,6c,00,49,00,3f,00,4e,00,7d,00,40,00,7e,00,70,00,34,00,4a,00,78,\
00,5d,00,43,00,48,00,4b,00,39,00,00,00,00,00
"ThreadingModel"="Apartment"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}\ProgID]
@="WeOnlyDo.wodFtpDLXCom.1"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}\Programmable]
@=""

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}\TypeLib]
@="{76250C3E-F846-4991-B2C9-8AA5718B3526}"

[HKEY_CURRENT_USER\Software\Classes\CLSID\{FE5B9A96-B1A7-4E8B-9713-115F51088981}\VersionIndependentProgID]
@="WeOnlyDo.wodFtpDLXCom"

Add these to your MST and you're good to go!