[VBA Chanllenge] in PowerPoint. Open/Close excel file in linked graph

Can someone help me writing this code: I want to open all the linked graph's excel and close it automatically without clicking any button. The reason for doing so is that I have an Embedded excel object in the powerpoint. All the Charts' excel reference the value from the embedded object. If I refresh the embedded object, I would have to open every chart's data in order to catch the changes (yes, it is annoying). Therefore, my idea is that if I would like to refresh, I could just simply open the embedded object and run the macro that automatically open and close the charts'excel. During the time that charts' excel is open, those values gets automatically updated. Thank you very much.

I don't think you need a macro for this. You can use the "update links" feature.

I'm using 2007 and it is located in:
File->info->Related Documents->Edit links
(related documents is in the bottom right - only appears if the file is saved)

Select all the files and choose "update now" - I assume you could program a vba macro to carry out this process manually if neccessary, it would be a lot quicker than opening all the files