File and Folder persmisison in Windows 2003 server (SP2)

HI..
I m using Windows 2003 server (sp2)
I have created user named ‘Param’,
shared drive ‘G’ for client.

I want to apply following permission / rights for ‘G’ drive

1) Admin can create folder/File delete / rename. ( i have done this, i have problem for following rights..suggest me tip to apply follwing rights)
2) Param can read these folder / files.
3) Param user must be able to modify files stored on ‘G’ Folder. (file type .doc, .xls etc..)
4) Param will not have rights to move/delete/rename the file or folder.
5) these security must be applicable to newly creted file / folder automatically.