The Denon RC-1098 is what’s known as an OEM remote (Original Equipment Manufacturer) and as such does not have a specific manual. It was supplied as the remote for Denon A/V Receiver models AVR-589, AVR-689, AVR-1609 and AVR-1709 and it’s instructions for use can be found within the manuals for these Receivers. Manuals for the AVR-1609 and AVR-1709 (English only) can be found here
The model number of the remote originally supplied with the AVR-2307 is RC-1043 (USA) and RC-1044 (Europe). Instruction manuals for these Receivers can be found here
(English) and here
Using a combination of these manuals, it may be possible to get a number of the functions of the AVR-2307 working by using the RC-1098, but in your case an RC-1043/44 would be better.ImagesRC-1098 RC-1043
Note that whilst there are a number of differences between the RC-1098 and RC-1043, the RC-1043 and RC1044 appear to be the same.