This article covers how to configure the export of reports when SQL Server Reporting Services (SSRS) is installed on a different server
Navigate to C:\Program Files\ManageSoft\Reporter\Web\
Open the web.config file
Configure the database server in the ManageSoft.Reports.MSReportingServer property
An example of this would be <add key="ManageSoft.Reports.MSReportingServer" value="http://MyDatabaseServer/ReportServer" />
Exporting of reports should now go through the database server.
See RMS Reference: Configuration: Configuring Reporting for more details