Allegro PCB designer: possible to export .brd to .mcm (Allegro Package Designer)?

Hi! Is it possible to export a PCB Designer (.brd) to Package Designer format (.mcm)? (or, equivalently, to import a .brd in Package Designer?)

We have a a 4-layer fan-out board for a flip-chip done in Allegro PCB (.brd), but the manufacturer is asking for .mcm files. Is it it possible to convert between them? Or does the board needs to be completely designed from scratch in Package Designer?

Thanks and regards, Jorge.