[Samba] Preventing Windows from changing file permissions

[av78us vaal]

Hi, 
Is there a way to configure samba such that Windows applications are not allowed to change file permissions for existing files in the share. 
I just want to be able to read and modify the files from Windows without affecting the file permissions inadvertently. I do not care about any Windows side file attributes such as ACL. 
I tried several things including parameters such as 'map archive = no', 'security mask = xxx' etc. Nothing seem to result in what exactly I want. This is surprising considering that my requirement is very simple. 
Is this possible in samba. 
thanks,Aneesh