This was never answered but I would appreciate a reply. I have made head-way but am frustrated with the lack of documentation on how to interact with named ranges.
Typically, my named ranges only refer to 1 cell or a group of merged cells. Because there isn't a clear path between the Named Range and a Cell object, I have the following code to parse the ReferesTo values. In my opinion, I should be able to get a CellSelection directly from the name.RefersTo value. Instead, I finally get the coordinates and create a CellSelection using this convoluted bit of code.
If getting the CellSelection this way isn't bad enough, when I finally submit the value it doesn't work. I put the value into a merged cell (1 row with 3 columns) and the v1 variable shows that the value is set when I view it in debug mode. However, when I open the document after running the code, the value is not there. However, the following line puts the same value in the columnIndex + 20 line and it shows up successfully in that location.
Is there a limitation around using Merged Cells?
(name.Name == nvp.Name)
 v = name.RefersTo.Split(
(sheet.Name.ToUpper() == v.Replace(
 r = v.Split(
columnIndex = ColumnIndexFromReference(r);
CellSelection selection = sheet.Cells[rowIndex, columnIndex];
RangePropertyValue<ICellValue> v1 = selection.GetValue();
sheet.Cells[rowIndex, columnIndex + 20].SetValue(String.Format(@
, nvp.Value, rowIndex, columnIndex));