Sorry but no. There is no way to set a fixed point in time at which these values are initialized within a watchlist column on Thinkorswim.
And even if you could, it would be utterly useless. The RSquared is computed using three elements:
- Weighted Moving Average
- Simple Moving Average
- StDev()
And the length is set to a value of 20. So if you could get it to initialize at 10 am, the values would not be fully computed until a total of 140 new bars have been added after 10 am.
So it seems your entire premise is flawed right from the start. Either that, or I completely misunderstood what you were requesting.