Proxy Rs 2005 - How To Use The ReportViewerWebControl.axd?

We have a reverse proxy for rs 2000 -> a client requests a report, it (the proxy) then goes out to the rs box, gets the report, encrypts any return urls and feeds the modified html to the requesting client. I understand this isn't necessary anymore with rs 2005 due to the architecture. Question is, when I use the ReportExecutionService.Render method it is still returning the parameters for the report, and not the ReportSession, ControlID, Controller, etc. parameters which hides the actual return values on the href links of the report.

Documentation is plentiful for rs 2005, but examples are not. Can someone please explain to me if using the new features in rs 2005 to hide the parameter values from the users is possible via web request? Making the parameter values completely and entirely (even via sniffer) is absolutely a must (which is why we are currently encrypting return URL's).

My code:

ReportExecutionService rs = new ReportExecutionService();
rs.Credentials = System.Net.CredentialCache.DefaultCredentials;
ParameterValue[] pvValues = null;
DataSourceCredentials[] credCredentials = null;
ReportParameter[] rptparamRequiredParams = null;
ParameterValue[] pvReportParameters = null;
ExecutionHeader execHeader = null;
ExecutionInfo execInfo = null;
rptparamRequiredParams = null;
string sHistoryID = null;

{fill parameters block}

rs.SetExecutionParameters (pvReportParameters, "en-us");

try
{
string extension;
string encoding;
string mimeType;
Warning[] warnings = null;
string[] streamIDs = null;
byte[] result = rs.Render (sFormat, sDeviceSettings, out extension, out mimeType, out encoding, out warnings, out streamIDs);
string d = System.Text.Encoding.ASCII.GetString(result, 0, result.Length);
HttpContext.Current.Response.Write (d);
}
catch
{
// do stuff
}

My code is returning:
http://henneseyjm1/ReportServer$sql2005?%2fJH.RSReporting%2fBAG&cy_start_date=1%2f1%2f2006&cy_end_date=3%2f1%2f2006&region=RG20&entity_num=nothing&proc_ctr=nothing&office_num=nothing&render_format=htm&view_name=standard&group_id=0&server_name=http%3a%2f%2flocalhost%2fJHnet%2f&user_is_office=False&rs%3aParameterLanguage=&rc%3aParameters=Collapsed&rc%3aToolbar=False

Where I would like it to return:
http://localhost/Reports$sql2005/Reserved.ReportViewerWebControl.axd?ReportSession=iyvsxg45vhzwd2acii3jj4q4&ControlID=de367546-919a-4f67-be4d-cd2747166dca&Culture=1033&UICulture=9&ReportStack=1&OpType=ReportArea&Controller=ClientControllerctl161&PageNumber=1&ZoomMode=Percent&ZoomPct=100&ReloadDocMap=true&EnableFindNext=False&LinkTarget=_top