Yes, you can get PCMCIA to CF adapters, so you can connect a secondary CF card in that slot. With the right drivers, the Amiga can even read FAT32 formatted cards, so it is very easy to transfer stuff back and forth from the PC.
This is one example:
http://amigakit.leamancomputing.com/...roducts_id=440
Just need to add a CF card as well, and maybe a CF card reader for the PC if you don't already have that.