Pat
You can do the following
1) Do as you did to create the Profile Line in Plan View
2) Create a HAL and use the 2D Line for the Wall as the HAL (use existing line)
3) Use the Copy to Profile Command to copy the Profile to the Profile View for a HAL - I would also copy the Grid Lines so that you have the Start and End Station markers of the Profile and the Min Max Elevation indicators (you can use this to scale the vertical in Profile view)
4) You need to scale the Profile Vertically to eliminate the exaggeration
5) You need to move the Profile in the Profile View so that the Start Station of the Line and the start station of the profile are the same
6) Now you can open the Vertical Tab of the HAL and then create a VAL and then append the profile to the Vertical Tab
7) You now have a HAL / VAL that you can use with Sideslope or Corridor - the VL is all grade breaks most likely but it will still work just fine.
There are videos on the forum from a while back on this
@Alan Sharp
Alan