Granting file permissions

Hi Experts!

BI is required to create a csv file when data is loaded, and place it in a directory in App server. Another system (XI) is going to read this file, and after reading , remove it to another folder in BI App Server for archival. Everything is happening in runtime... no manual intervention.

My requirement is to grant read & execute permission to the XI user so that it can read and then remove the file. How can I do so? It is a one time activity, so that permission can be given for XI user for all files? Or do I have to give permissions for each file when it is created?

If so, then how can i give the permission while creating the file?

This is a very urgent requirement, so please help me with this.

Thanks

Sushmita