From the menu Edit → ASCOM … Setup.
The menu include an entry for each defined ASCOM device. This open the ASCOM driver setup dialog for your device to let you set any specific option for the devices. Please note this setup dialog is not a part of CCDciel but a part of the driver.
Beware that the device must be disconnected before the Setup dialog can be opened. This is from the ASCOM specification and cannot be changed.
If it is already connected a dialog prompt ask your confirmation before to disconnect the device, it is reconnected when the setup dialog is closed.
This fail if the device is also connected to another application because CCDciel cannot act for the other application. In this case you have to disconnect the device from the other application first.