Hi,
I did some tries and found that, even if i'm unable to tell Notes, when it installs, the notes.ini file location it should use, i still could achieve what i wanted.
Before installing on the Citrix box, i mapped the network share whith all the notes stuff to the letter L:, and then launched the install command: setup.exe /s /v"SETMULTIUSER=1 MULTIUSERBASEDIR=L:\!USERNAME! MULTIUSERCOMMONDIR=L: CITRIX=1"
Then, when the user logs on, i run a script containing:
net use L: \\file_server_name\share_name
reg add HKCU\Software\Lotus\Notes /t REG_EXPAND_SZ /v NotesIniPath /d "L:\%username%\notes.ini"
If the key doesn't exist, the first notes launch process creates the reg key with a REG_SZ type key; but, by chance, if the key exists, it doesn't care about the type, so, a REG_EXPAND_SZ type key can then contain the %username% variable.
The notes client still creates the IBM\Notes\Data structure in my L: folder but it's empty and he uses the existing notes.ini file located in L:\, allowing the files update to the new client version.
Perhaps this helps someone else ,
Yan