You can dynamically generate a one time subscription in SSRS for the report. You'll have to use the RS webservice as mentioned by Diego.
Your code would look something like this:
static void generateSubscription()
{
if (SubscriptionRequests.Count < 1) return;
NetworkCredential credentials = new NetworkCredential("user", "pass");
reports.ReportingService2005 rs = new reports.ReportingService2005();
rs.Credentials = credentials;
DateTime topDatetime = DateTime.Now;
topDatetime = topDatetime.AddMinutes(2);
foreach (SubscriptionRequest x in SubscriptionRequests)
{
reports.ExtensionSettings extensionSettings = new reports.ExtensionSettings();
List<reports.ParameterValue> extParameters = new List<reports.ParameterValue>();
List<reports.ParameterValue> parameters = new List<reports.ParameterValue>();
string description = "Email: ";
string eventType = "TimedSubscription";
extensionSettings.Extension = "Report Server Email";
string scheduleXml = "<ScheduleDefinition><StartDateTime>";
scheduleXml += topDatetime.ToShortDateString() + " " + topDatetime.ToShortTimeString();
scheduleXml += "</StartDateTime></ScheduleDefinition>";
parameters.Add(new reports.ParameterValue() { Name = "abc", Value = x.id });
extParameters.Add(new reports.ParameterValue() { Name = "RenderFormat", Value = x.renderFormat });
extParameters.Add(new reports.ParameterValue() { Name = "TO", Value = x.email });
extParameters.Add(new reports.ParameterValue() { Name = "ReplyTo", Value = x.replyTo });
extParameters.Add(new reports.ParameterValue() { Name = "IncludeReport", Value = "True" });
extParameters.Add(new reports.ParameterValue() { Name = "Subject", Value = "subject - " + " (" + x.id.ToString() + ")" });
extParameters.Add(new reports.ParameterValue() { Name = "Comment", Value = x.body });
extensionSettings.ParameterValues = extParameters.ToArray();
description += topDatetime.ToShortDateString() + " " + topDatetime.ToShortTimeString();
description += " (" + x.a + " - " + x.b + " - " + x.c + ")";
string _reportName = "/report";
rs.CreateSubscription(_reportName, extensionSettings, description, eventType, scheduleXml, parameters.ToArray());
topDatetime = topDatetime.AddSeconds(30);
}
}