qgis 2 - Plotting points that have relative coordinates rather than total station coordinates on map?

I have about +100 points of various descriptions from an archaeological survey. They are the backlog from years of excavations BEFORE systematically using Total Station at the site. For each artifact I have the upper and lower elevation data, in addition to the distance from either the NE, SE, SW, or NW point of the grid square. The location was recorded using two meter tapes from two points intersecting at the point of the artifact. The Excel file I have records the grid corner point and the distance from that corner to the artifact (ID1 and Radius1, ID2 and Radius2).

First, I need a method that will help me systematically upload the points. How do I arrange my Excel file, and what do I do in QGIS to get it plotted properly?

Second, I want to be able to answer questions of spatial relations based on elevations.Is there something special that I need to do for the input of the data in the .csv file?

I'm new to QGIS.