Hi,
Based on my understanding, you want to access the file that exists in remote FTP server from your ASP.NET website, right?
If so, we can use FtpWebRequest class (http://wiki.asp.net/page.aspx/283/ftpwebrequest/) to download this file from FTP server and then send it to client.
To display this flash while page is loading, we can use Div tags to contain flash, and use JavaScript to change its display attribute to none while page is loaded.
For example, see
<body onload="document.getElementById('flashContainer').style.display = 'none';">
<div id="flashContainer" style="display:block">Play Flash. . .</div>
I look forward to hearing from you.