Bart,
Did you create the file in AC23? if so you can simply do a ‘Save As’ and save as an AC22 file. If you created the file in a trial
Version of AC23 you are out of luck as the files created in the trial version can only be opened on a full version installed on the same machine the trial was installed on.
If you received the file from a 3rd party you should ask them to save as an AC22 file, they should have no problem doing this if you have permission to use the design and have paid all fees etc
Regards,
Scott