The short answer is: you cannot. Some macros (and according to the documentation and to the project's I've been working in), the OnPostReload will not work in a server-client environment. So you will have to manually click on the button that triggers the macro or something because this is not allowed for the time being.
You can try anyway, there are some people here for whom these macros seem to work. Actually I'd be glad to check that that's possible.
If you are using Publisher, there may be some tasks other than Reload that may be helpful (Distribute) but this is a different license.
the easiest way to solve your problem is NPrinting: it can export data from QlikView to Excel withou writing macros. You can export Qlikview chart as is or you can made your own excel export template with a intuitive excel based editor. After you can shedule QlikView activities with tasks: for instance the first could be a data reload so your QlikView document is update, the second could be the export to excel filtered and sended via email or saved to specific folder.