public object MyFunc(object range) { string retVal = string.Empty; try { if (range is Excel.Range) { Excel.Range xlRange = range as Excel.Range; try { int row = xlRange.Row; int col = xlRange.Column; retVal = "The range address is: [" + xlRange.get_Address(row, col, Excel.XlReferenceStyle.xlA1, Type.Missing, Type.Missing) + "]"; retVal = retVal.Replace("$", string.Empty); } finally { Marshal.ReleaseComObject(range); } } } catch { return(CVErr(AddinExpress.MSO.ADXxlCVError.xlErrNull)); } return(retVal); }