Martin,
To use your own drivers with a Custom Recovery Disk you must enable "Delete Drivers" and "Prompt for Drivers" during the recovery operation.
To do this, after selecting your Recovery Points, when the Restore Anywhere checkbox page comes up, press Ctrl and Shift before checking the Restore Anywhere checkbox and the two additional checkboxes mentioned above should appear. These will allow you to load your own drivers.
After the Recovery Point has loaded (approx 99%) System Recovery will check your hardware and prompt you for drivers. Dell has a nice utility (make_driver_dir.exe) included on their setup disk that copies drivers for a specific O/S and platform (their servers) into a directory of your choice. I set this up in the same location as the Recovery Points so they would be available at the same time.
Good luck.