Ideal DVD Copy can't recognize iso file directly. If you have saved your DVD-Video movies as .iso file, you may use a virtual software such as MagicDisc (a freeware) to load your ISO file to a virtual drive first, then you may just chose that virtual drive in ideal dvd copy as the source.
And you may follow the steps below to learn how to load .iso file to your virtual drive.
Right click MagicDisc trayicon
Select "Virtual CD/DVD-ROM"
Select one of virtual CD/DVD drivers. (for examples: H: No Media)
Click "Mount"
Browse and select the CD/DVD image you wish to mount.
Click "Ok"