That is a very kind offer, only if you are at a loose end. All I have on Charles is as follows:
Parents, William Miller 1719-1794 and Elizabeth Cummings 1716-1788 of Nether Tomdow Farm, Knockando, Morayshire
Illegitimate children Sarah 1785 and James 1787 who he had in Knockando with the widow Janet McAllister alias McDonald of Nether Borlum Farm.
His brothers are Hugh and John
His sisters are Isabella and Margaret ?-1789.
There is no record of brother John on the stone so he is likely to have died after his father, between 1794 & the mention of him as deceased in 1796
According to Kirk records when the illegitimate births were discussed, Charles visited Knockando regularly on business from Durham, South Britain. He isn't buried in Knockando. There was a fire in the 1780s and all Kirk records before that date are lost.
And that is it!
I feel fairly sure he must have a wife somewhere as he didn't marry the widow but if he married the wife in Knockando before 1783 the record will have been lost. I must try to get into those Kirk Session records again to look for more clues but unfortunately they're in Edinburgh and I'm not. You are so lucky to have all of those records on-line in Durham. I'm going to have to try to get to grips with them. Thanks for all you've done.