Script for automatic history loading

I need a MT5 script which will load a X number of bars for every pair and every TF (from M1 to MN). It has to go trough all currency pairs listed and update history bars for all time frames (from the broker).

I'd need my MT5 platform to be able to update bars for every currency pair. I have a situation where not all bars are loaded, that's the reason why I need this script.

Basically I want to run the script, and the script will go trough all pairs and update bars that are missing.

I will have to have the source code, so I can incorporate it in my custom indicator. It has to be script, not an EA.