SharePoint SQL data retrieval

Hi

I need to provide list data to an external system. Once the data has been accessed, we need to write a flag to the list as accessed.

The external system will probably be another SQL Server query. This query will grab info from sharepoint and other systems, and feed it to a dialler.

For the external SQL to access and write to  the list on SharePoint I was thinking of providing access directly to the SharePoint SQL server. Is this a good idea? Is there better and safer way?

Using SharePoint Standard Edition. But options for enterprise welcome.

Thanks