just my 2 cents...
Excel is totally not the tool of choice for what you want to achieve...
Even if it might be possible, for reasons stated by a few persons already, you won't get much help here, simply because it would be something too easily exploited for less helpful purposes...
Also, if you plan on using Sendkeys, I predict many sleepless nights in your future... Sendkeys is notoriously unreliable, the moment the user does anything at all you did not account for, things start to go wrong: where you think you are using it to acknowledge a start installation dialog, the user might just have selected a bunch of files and accidentally pressed delete, upon which you then confirm the action, leaving the user stunned and probably angry...
If you want to automate installation processes, I suggest you look into tools like AutoIt