Erm.... no idea, sorry. =)
Embedding objects into batch files doesn't work, obviously, because batch files don't have anything to do with anything that isn't arcane or related to DOS 6.1 (or prior)!!!
As far as I know, and this is by no means conclusive, you can't set-up your own parameters to pass into Flash from the HTML file. What you could do though is pass them in the HTML header. So for example when you call the page with your movie on call it with something like:
'my_page.html?username=petitpal&password=petitpal&'.
Obviously this has certain security issues, so you could put the variables into a form on the previous, calling, page and do a submit, which passes them in a 'hidden' way. Again though this has secruity issues.
If you want to do either of these then when you go into the Flash movie you do a 'load variables' jobby and you get the username and password variables passed into your movie from the HTML page.
The only real way to get decent security though is to use something like ASP on an SQL database, or just an SQL database, and process the secruity stuff on the server side. Any client side secruity thing you do with Javascript, etc, is just going to be dodgy.
I suppose the way round it (not that I'm thinking as I'm typing you under stand

) would be (and I know this is a bit of a bodge) to pass the username in via a batch file, or HTML page header / form variable and then have a text file with a list of users passwords. Set-up something like this:
petitpal=petitpal&nigel=havers&username=password&
You could then do an eval() on the username (so it reads the contents of the username variable as a variable in its own right, and then check that when the user enters their password it matches this...
Anyway, that long winded mail brings me to a halt. =)
If i've gone a bit incoherent half way down (which is possible) - just let me know or e-mail me or something =)
bye for now!
=)
PetitPal.