how do I use a linear regression model on a specific case not in the DB, and get the prediction WITH a confidence interval?

I wish to use the prediction model for a specific case not in the DB, without adding a line in the DB.

1. How can I do an automated calculation of the prediction (I mean: put parameter values, and get the prediction (average and Interval)
2. How do I get an interval of confidence of the prediction?

I find no way in the menus.