You can't normally read data from an LCD, most are 'output only' devices and have no method of reading back their character memory.
If you mean to display the same data on a second display which is a 7-segment type, the easiest solution is to use a dedicated display driver IC. The MAX7219 comes to mind but I think it has been superceeded by newer types. These devices do everything for you to display up to 8 digits, including all the multiplexing but you can chain them together to add more digits if needed. You should be able to drive it from a parallel port and at the same time as an LCD because their control protocols are completely different.
Brian.