you need transform the point from global to local coordinates. There are many transforms happening in SolidWorks. If you are working in a part it's pretty straight forward as below. If you are in an assembly looking at a point in a component there is a transform for the component that comes into play. On top of that in a drawing there is a view transform that needs to be accounted for. I'll leave the excel work out of this post. I have a complete macro to do this but unfortunately I can not share the entire macro here but I can share the basic technique required. Hope this helps. I pulled out some my code but this is not tested as is but works in my final code.
Dim swApp As SldWorks.SldWorks
Dim swModel As SldWorks.ModelDoc2
Dim swFeat As SldWorks.Feature
Dim swCsys As SldWorks.CoordinateSystemFeatureData
Dim swTransform As SldWorks.MathTransform
Dim swPt As SldWorks.MathPoint
Dim swLocalPt As SldWorks.MathPoint
Set swApp = Application.SldWorks
Set swModel = swApp.ActiveDoc
Set swMath = swApp.GetMathUtility
Set swFeat = swSelMgr.GetSelectedObject6(1, 0) 'assumes the Csys is the first item selected.
Set swCsys = swFeat.GetDefinition
Set swTransform = swCsys.Transform
' Code to get the point to work with goes here
Set swLocalPt = swAssyPt.MultiplyTransform(swTransform.Inverse)