Millen was drafted in to manage the team following the departure of Tony Pulis before the start of the new Premier League season, while director of football Iain Moody resigned on Thursday due to the investigation looking into his conduct while working with Malky Mackay at Cardiff City.
The two exits have forced Millen to play a more prominent part in the transfer market, with the club still eager to bring in players over the next couple of weeks.
"It will go through me really now," the temporary Palace boss told reporters. "I've asked the scouting department to have a meeting with me today, to discuss the names that we feel we can bring in. I'll speak to the chairman then.
"The process has got to be ongoing, and if we do appoint a manager, we can say 'this is what's out there, this is what we think we need', and then hopefully it will be the new manager's final decision."