Hi Luca,
I'm not sure if any of the ideas below will get you want you need, but first let me hasten to add that you can certainly use the latest versions of our software (10.x) for re-processing your data, just not for acquiring data on your SX50. Since we have added many new re-processing features since v 9.x, you should update all your off-line computers to 10.x right away.
In the meantime did you try the Export Single line format here:
![](https://probesoftware.com/smf/oldpics/i43.tinypic.com/f3ztpx.jpg)
The Excel file this creates has the elemental concentrations but also the oxide formulas for each elements, so it would be simple to convert them in Excel.
You can also get a list of your standards in any Probe run, by clicking the Run | List Standard Compositions menu. This produces this type of output (note the OXWT: line):
![](https://probesoftware.com/smf/oldpics/i44.tinypic.com/epj39v.jpg)
Does this help?