// init app emulation model
  $appEmulation = Mage::getSingleton('core/app_emulation'); 
  
  // Start environment emulation of the specified store
  $initialEnvironmentInfo = $appEmulation->startEnvironmentEmulation($store_id); 

  /**
   * Any code thrown here will be executed as we are currently running that store
   * with applied locale, design and similar
   */

  // Stop environment emulation and restore original store
  $appEmulation->stopEnvironmentEmulation($initialEnvironmentInfo);