string GetReferenceR1C1(
    Cell baseCell
)

Function GetReferenceR1C1(
    baseCell As Cell
) As String

using DevExpress.Spreadsheet;
// ...

IWorkbook workbook = spreadsheetControl1.Document;
Worksheet worksheet = workbook.Worksheets["Sheet1"];

CellRange range = worksheet.Range["B3:D5"];

// Returns the range reference relative to cell E7 - "R[-4]C[-3]:R[-2]C[-1]".
string refRel = range.GetReferenceR1C1(worksheet.Cells["E7"]);

// Returns the range reference relative to cell A4, including the worksheet name - 
// "Sheet1!R[-1]C[1]:R[1]C[3]".
string refSheet = range.GetReferenceR1C1(ReferenceElement.IncludeSheetName, worksheet.Cells["A4"]);

// Returns the mixed range reference (with absolute row reference and column reference relative to cell B2),
// including the worksheet name - "Sheet1!R3C[-1]:R5C[1]".
string refMixed = range.GetReferenceR1C1(ReferenceElement.RowAbsolute | ReferenceElement.IncludeSheetName,
                                        worksheet.Cells["B2"]);

// Returns the absolute range reference - "R3C2:R5C4".
string refAbs = range.GetReferenceR1C1(ReferenceElement.RowAbsolute | ReferenceElement.ColumnAbsolute, null);

Imports DevExpress.Spreadsheet
' ...

Dim workbook As IWorkbook = spreadsheetControl1.Document
Dim worksheet As Worksheet = workbook.Worksheets("Sheet1")

Dim range As CellRange = worksheet.Range("B3:D5")

' Returns the range reference relative to cell E7 - "R[-4]C[-3]:R[-2]C[-1]".
Dim refRel As String = range.GetReferenceR1C1(worksheet.Cells("E7"))

' Returns the range reference relative to cell A4, including the worksheet name - 
' "Sheet1!R[-1]C[1]:R[1]C[3]".
Dim refSheet As String = range.GetReferenceR1C1(ReferenceElement.IncludeSheetName, worksheet.Cells("A4"))

' Returns the mixed range reference (with absolute row reference and column reference relative to cell B2),
' including the worksheet name - "Sheet1!R3C[-1]:R5C[1]".
Dim refMixed As String = range.GetReferenceR1C1(ReferenceElement.RowAbsolute Or ReferenceElement.IncludeSheetName, _
                                                worksheet.Cells("B2"))

' Returns the absolute range reference - "R3C2:R5C4".
Dim refAbs As String = range.GetReferenceR1C1(ReferenceElement.RowAbsolute Or ReferenceElement.ColumnAbsolute, Nothing)