There appear to be a number of suggestions to do this, non of which appear to work.

Effectively, I'm wanting to change a text value in an Excel sheet to a number (this is a cell that has been set as a number stored as text, and has a green diamond next to it).

This [webpage](http://www.dailydoseofexcel.com/archives/2006/02/18/number-stored-as-text/) details how to resolve the issue in Excel, through the UI, and I've recorded this as a macro below (but that's VBA)...

Including setting the value to itself:

```
                Range allCellsRng;
                string lowerRightCell = "AZ500";
                allCellsRng = wSheet.get_Range("A1", lowerRightCell).Cells;
                foreach (Range cell in allCellsRng)
                {
                    if (cell.Value2.ToString().Length > 0)
                    {
                        cell.Value2 = cell.Value2;
                    }
                }

```

This is a recorded VB Macro, that shows what will resolve the issue, but I'm having problems representing this in C#:

```
ActiveCell.FormulaR1C1 = "0"
Range("A1").Select
Selection.Copy
Selection.PasteSpecial Paste:=xlPasteValues, Operation:=xlAdd, SkipBlanks _
    :=False, Transpose:=False
Range("A1").Select

```