You can use open collector or open drain logic devices (inverter or not inverter buffers), adding pull-up resistors in the outputs.
Connect the +VCC/+VDD pin of the buffer to 5V if their inputs are driven by the uC. Connect this pin to 12V if their inputs are driven by your CMOS (12V supply).
Connect the pull-up resistors to +5V if they are to drive the uC inputs. Connect them to 12V if they are to drive the CMOS inputs.
In any case, the buffers have to be specified to support the power supply you apply to them, and also to support in their (open) outputs the voltage level applied to the pull-ups.

It seems more complex than it really is, all beacuse I don't express my ideas in a very clear way using English. Sorry.

Alfredo.