Interpolation while making adjustments in model object

[BT454]

Good afternoon!
I'm attempting to use interpolation to make some adjustments to a forecasted series in the model object.
It's been a while since I've used it, but I recall being able to simply enter a value in the first period of adjustments, a different value in the last period, and use the @ symbol in the second period to automatically fill in the interpolated values. Is this functionality still available?
Thanks!
Bob