No code needed. You could create a data connection to the file in the form library using Excel's Get External Data method and map the XML contents that comprise the file to Excel.
In Excel, on the Data tab, in the Get External Data group, click From Other Sources. Choose From XML Data Import. In the Select Data Import dialog box, navigate to the form library on your SharePoint site. It should resemble this format (both https):
In 2013: //[your domain].sharepoint.com/[site]/[form library]
In 2010: //sharepoint.[your domain].com/[site]/[form library]
(If this doesn't work, you'll need to get the webDAV address to your SharePoint library by either mapping a network drive or by using the Open with Explorer feature in the Library tab of the Ribbon in your form library and get the address from there.)
Click OK. In the Import Data dialog box, select XML table in existing worksheet, select a range in Excel, click OK. (You should also check the XML map properties before clicking OK and make sure that the Save data source definition in workbook checkbox is checked.)
The InfoPath data is now mapped to your Excel workbook and you can refresh the data as needed.