Be careful, or the WotC C&D attack hammer will find a new target to beat into submission! That being said, somebody may well have added the new material you desire already (not me, I am not skilled enough with Excel to do that). The artificer is especially tricky, as it is an entirely new class and the custom page of the generator is not set up to handle entirely new classes.
You might also want to check out the Aurora Builder program, which has an active community that adds new and 3rd party materials regularly. It uses the standard D&D character sheet, which I personally do not care for, but it is actively updated.