Changing decimal separator in charts (comma to dot)

[N_Aggelopoulos]

In most (maybe all) European languages other than English, a comma is used as a decimal separator where in English there is a dot. So the German version of Microsoft has the comma as the default decimal separator. It is possible to change this in Excel and have the dot as the decimal separator. However, when importing a graph from Excel to PowerPoint, the values revert to having a comma as a decimal separator, so 0,5 rather than 0.5. Since I want to make my presentation to a scientific conference where English is the official language, I would like to use throughout the PowerPoint presentation (including graphs imported from Excel) the English style, with the dot. It seems that changing the language to English does not affect what decimal separator is used in the graphs. Is there some other way to achieve this?

I attach a graph imported from Excel into PowerPoint to illustrate the problem. In Excel, the commas had been changed to dots by editing the advanced settings but when the graph is imported to PowerPoint, the decimal separator reverts to the comma.