Once you have retargeted animation to rig, and perhaps adjusted it to make it just right, you can plot (bake) that resulting animation into fcurves that are applied to the rig's animation controls. This makes it easy to work with the animation in Softimage so that you can edit it in a normal way.
To plot the mocap data onto a rig
Choose either Tools 
MOTOR Mocap to Rig or Rig to Rig from the Animate toolbar to open either the Mocap to Rig or Rig to Rig property editor.
Click the Plot button at the bottom of either of these property editors to open the Plot Tool dialog box.
In this box, you can set up what the plotted fcurves will be:
Select the Preserve Source Keys option to keep the original keys from the animation on the rig, if the retargeted animation was created from keyframes.
Select the Key Peak, Valley, and Inflection Points to set keys on these points of the animation data.
Select Key at Interval Spacing to set keys only at certain intervals in the plotted fcurves. If you select this option, you need to set the Interval Size, which is the interval value. For example, if you specify 2 as the Interval Size, a keyframe is created only on every other frame on the plotted fcurve.
Set the Start and End Frames to specify the frame range that you want to plot.
The plotting process removes the mocap data and retargeting operators from the animation controls, turns the motion data into fcurves, and fits those curves using the best tangency possible given the key Interval Size information. The plotted fcurves are then applied to the animation controls.
For some animation controls, such as the feet, extra keys may be created in order to have better animation, such as where the feet come in contact with the ground.
You can now select the animation controls and edit their fcurves as you normally would in the fcurve editor.