Is it possible to connect an application to an external Excel-sheet, which is placed in Google Docs?
You really need to be more specific. What do you mean by "connect an application" to the Excel sheet? Google Docs has an API that you can get to the files. Is this really an Excel spreadsheet or is it a Google Doc "Sheet"? Etc.
It is a google docs spreadsheet. Otherwise I could download the sheet to Excel and 'Import Entities from Excel'.
Now I need a database, which can be updated by several people through Google Docs.
You will need to look at the Google Docs API to see if it supports what you are trying to do. If the users are updated a shared spreadsheet, why not just have them log into your applcation and update the data there?
Thans for your reply. I totally agree with you about logging into the application, but as you might know, some companies don't like major changes ;)