I'd like to know if it is possible to create a VB.net application that monitors the usage of certain Excel workbooks.
The desired process is as follows:
1. I give a model which is created with Excel to my client
2. I want to licence that model for one year at a time
3. The user is required to install an external (VB.net) application that monitors the usage of this Excel workbook
4. If the licence is in force, the saving/modifying of that workbook is allowed
5. If the licence is expired, the saving/modifying of the workbook is disabled
My current problem is that I am not able to licence my Excel workbooks. I can't use third-party products for licensing the workbook, because the user has to be able to open the workbook if he/she created/saved it during the time when the licence was in force. The user can and in this case will save the workbook under a new name many times and has to be able to reopen those workbooks even if the licence has been expired (assuming they were saved when the licence was in force). If I use a third-party product to lock the workbook, I suppose any of them cannot be opened when the licence is expired.
That's why I thought if it is possible just to prevent saving and modifying the Excel workbook with VB.net application if the licence is not in force. That would make the model pretty much unusable (like a read-only file).
The workbook should also not open in any case if the VB.net application is not running simultaneously (the VB.net application monitors the open event of any workbook, check if the workbook is the one I sent, check when it was saved and then prevents opening or opens it either with full rights or only with read-only rights, based on the current licence status)
The workbook formulas should also be prevented to be copied and VBA code prevented to be accessed, so that the user cannot recreate the model in any way.
Has anybody experience/ideas of how that kind of licencing procedure can be established?
The desired process is as follows:
1. I give a model which is created with Excel to my client
2. I want to licence that model for one year at a time
3. The user is required to install an external (VB.net) application that monitors the usage of this Excel workbook
4. If the licence is in force, the saving/modifying of that workbook is allowed
5. If the licence is expired, the saving/modifying of the workbook is disabled
My current problem is that I am not able to licence my Excel workbooks. I can't use third-party products for licensing the workbook, because the user has to be able to open the workbook if he/she created/saved it during the time when the licence was in force. The user can and in this case will save the workbook under a new name many times and has to be able to reopen those workbooks even if the licence has been expired (assuming they were saved when the licence was in force). If I use a third-party product to lock the workbook, I suppose any of them cannot be opened when the licence is expired.
That's why I thought if it is possible just to prevent saving and modifying the Excel workbook with VB.net application if the licence is not in force. That would make the model pretty much unusable (like a read-only file).
The workbook should also not open in any case if the VB.net application is not running simultaneously (the VB.net application monitors the open event of any workbook, check if the workbook is the one I sent, check when it was saved and then prevents opening or opens it either with full rights or only with read-only rights, based on the current licence status)
The workbook formulas should also be prevented to be copied and VBA code prevented to be accessed, so that the user cannot recreate the model in any way.
Has anybody experience/ideas of how that kind of licencing procedure can be established?
