Proxy issue while calling dataloader from c# code

I am using a c# code to execute dataloader command in order to upload a csv to salesforce.

ProcessStartInfo dataLoaderProcessInfo = new ProcessStartInfo();
        dataLoaderProcessInfo.FileName = "java.exe";
 dataLoaderProcessInfo.Arguments = command;
        dataLoaderProcessInfo.UseShellExecute = false;
        dataLoaderProcessInfo.RedirectStandardInput = true;
      dataLoaderProcessInfo.RedirectStandardOutput = true;
        //Start the Process
        Process dataLoaderProcess = new Process();
        dataLoaderProcess.StartInfo = dataLoaderProcessInfo;
        dataLoaderProcess.Start();

        //Read/Write to/from Standard Input and Output as required using:
       // var v = dataLoaderProcess.StandardInput;
        var output =  dataLoaderProcess.StandardOutput.ReadToEnd();
        dataLoaderProcess.WaitForExit();
        return output;

The command that i am using is a string which is as below

var command = "-cp \"C:\\Program Files\\salesforce.com\\Data Loader\\dataloader-30.0.0-uber.jar\" -Dsalesforce.config.dir=\"D:\\Amex-desktop\\Registrationportal\\accountInsertMap\" com.salesforce.dataloader.process.ProcessRunner dataAccess.name=\"D:\\Amex-desktop\\Registrationportal\\accountInsertMap\\insertAccounts1.csv\" process.name=\"accountInsert\"";

So internally I am using dataloader-30.0.0-uber.jar from dataloader installation to upload the csv. The issue is this code works fine when I am in public network but gives access denied to proxy exception from my office network. I understand that it might be due to proxy not able to access the salesforce endpoint but not able to understand why I am able to login using dataloader UI application from the same network and same proxy.