ExternalLinks referenced in an Excel sheet of type .xls and .xlsx

Mar 15 at 7:18 AM
I am new to NPOI development. Currently, working on a project involving NPOI. I have a scenario where I need to parse all cells in an Excel sheet to find out formulas and ExternalLinks, if any. I was successfull in finding out the formulas underneath a cell but not the External links.I was able to get the value of the file the external link is pointing to (for example, '[Test.xls]Guest') but not the full path like "='C:\Files[Test.xls]Guest'!F13" the cell underneath is pointing to. I used "cell_Active.CellFormula.ToString()" to get the value '[Test.xls]Guest' but not the full path. I read several documents on internet but couldn't get what I need.
My simple question: How to get ExternalLinks referenced in an Excel sheet of type .xls and .xlsx? If I am not wrong, we need to use HSSF for files of type .xls and XSSF for files of type .xlsx.