AutoCAD Inventor :: Constraining A Part To A Sketch Point In The Assembly Environment

Unfortunately, it's chock full of proprietary customer data, so I can't share the parts or the assembly.  But I can pretty well explain what needs to happen, and I've attached a JPG that shows a bit of what I'm doing.

I need to design a bracket to hold an RPM sensor at a certain gap to a spiral bevel gear.  I've got a huge assembly model (non-Inventor) from the customer, as well as the model for the sensor.  My plan is to start a master IAM, insert the customer assembly, insert the sensor and constrain him, and draw the various hardware I need around the sensor.

So I start by making a work plane that matches the bevel angle and is in a location so the end of my sensor will be flush to that plane.  Create a sketch on that plane, then project 2 relevant axes to create the appropriate "origin" from which my location will be based.  Place a point on one line, at a certain radial distance and constrain my point.

So now I've got a point and a plane that are where I want my sensing face and my centerline axis to be.  What now?  I was thinking that I'd create a work axis "normal to plane through a point", but this workflow isn't available in the assembly environment.  I can't constrain a solid to a sketch point, so I really don't know what to do at this point in order to put the part where I need it.