Using Drive Image 4.00/Partition Magic

Having recently purchased these product, and they are good, Ihave a problem, In my infinate wisdom I had previosly aquired a cdrw of the external nature[usb]thinking I could do all kinds of magic on the hoof!!
The problem is that the above softies do not support external cdrw’s does any one know a workaround, or any useful advice, cos this is like having a car with no engine!!!1
Steve