UPDATESKETCH command
Changes the parameters of the sketch features.

Description
Allows you to modify a parameter of a sketch feature.
Note: The EXTRUDE, LOFT, SWEEP, and REVOLVE commands and their children features SUBTRACT, and UNITE, create sketch features when the CREATESKETCHFEATURE system variable is ON. They are available in the Mechanical Browser panel.
Method
Specify the feature name, then the parameter name, and set the new value for it.