"It is pretty amazing," McDonald told the Weekend Herald before flying out of Sydney on Wednesday night.
"Obviously this has all happened pretty quickly after I have come back so it is a great buzz.
"Ascot is amazing and I am indebted to Charlie Hills [trainer] to get a ride like this and all his support.
"So hopefully I can get a win. I have had a couple of seconds there but to win one at Royal Ascot would be special."
McDonald has been riding at least a winner a meeting in Sydney since returning on May 16 and has made a mockery of the cynics who suggested his time away from the saddle - for having a $1000 bet placed on one of his own rides for him by a punter friend - would end his career.
His weight, which was supposed to be the comeback issue, has been remarkably stable.
"I can ride 55kg at the moment but it will be harder now as I start trying to get down to the 54kg or even lower on occasions.
"But my weight is definitely better than it used to be and having a partner [now former jockey Katelyn Mallyon] in my life helps with a more stable lifestyle."
McDonald's comeback has so far almost felt like a wonderland warm-up before things get really serious next season.
"I am not making any secret of the fact I will be chasing the premiership and will ride in Sydney predomin-antly but I am also looking forward to getting to the carnival in Melbourne again and being part of that.
"But I'd love to win the premiership and hope the level of support I have had from trainers will continue because so many people have been great since I came back."
That was to be expected though McDonald is not only hugely popular within the industry but in a town as ruthless for winners as Sydney his skills were always going to be highly sought after.
But Ascot, during the Royal meeting, against the likes of Ryan Moore and riding in front of the Queen just a couple of months after he wasn't allowed to set foot on a racetrack?
If McDonald rides a winner next week it may go down as his most incredible achievement yet.
Awesome Ascot
•Royal Ascot in England starts overnight Tuesday, NZ time.
•Kiwi superstar jockey James McDonald has one of his best chances of winning a race at the glamour carnival.
•McDonald hopes to have at least 10 rides at the meeting just six weeks after returning to race riding.