In response to your question, I would say 'maybe'... I do not know of a way to satisfy the parameter value through code directly like you are wanting to do. It may be possible, but I doubt that it's very common, therefore you're not likely to find much about it on the internet, nor in MS help files. A parameter query is specifically constructed to require user participation, so therefore, attempting to short-cut this by background calculation is not likely to have very many proponents.
This MS article provides a possible work-around in that it involves creating a form to collect the user parameters. (btw you are right, something I didn't know, but is mentioned in the article is that the report On Open event fires
before the RecordSource is queried).
You could possibly use this form to do the calculations you wish, simply opening it hidden, making it do the calculation and then closing it with the report.
Good luck!
Regards,
Scott