How do I allow writing to a single file in readonly directory

[Jeff Ballin]

Greetings everyone,

Well, I am stumped.  I have read the documentation, perused the lists,
so if the answer is out there, please point me the way.  I am running
Samba 2.0.7 on an Alpha RedHat 6.0 system.  Everything seems to work
great in general.  However, we recently installed SigmaPlot 6.0, and
it insists on writing to a file (lockfile.sys) in the root directory
of the program (\\server\winnt\Program Files\SigmaPlot6), which is
located in a read only directory.  I would like to allow only this
one file to be overwritten, but nothing else.  Currently, because users
do not have write access to this file, loading the program fails with
an error saying that it cannot write to/create this file.  If I log
on as administrator (with write privileges to that directory), the program
loads fine.

The lockfile.sys file is chmod 777 in a directory that is chmod 755. 

Below is a clip from my smb.conf file:

[winNT]
        comment = Windows NT File Share
        path = /winNT
        revalidate = Yes
        write list = @adm
        writeable=yes
        guest ok = Yes
        max connections = 10
        locking = Yes
        share modes = Yes 

There is nothing in the global section that looks like it would affect
anything like locking, write access, etc., but if anyone is interested,
I would be happy to send it along.

Thank you very much for your help.  Best wishes,

Jeff Ballin		jeff at biochem.wisc.edu
Record Lab SysAdmin
University of Wisconsin-Madison