Dhtmlx Connector, how to load records from desired posStart

My configuration is dhtmlx grid 3.5 pro and Java Connector to render sql directly to dhtmlx grid.

I need to refresh/load grid content and show record on desired posStart.
No,w Im using onXLE and first scroll to desired posStart (rows are loaded) and then selecting row by calling selectRowById.

The problem is that ever load starts with loading first 0-30 records, how to avoid this?

Unfortunately there is no way to avoid it when you fully reloading grid.
You can try to use updateFromXML method instead of the full reloading, it will update only the loaded set of rows, and will not cause any unnecessary loading calls.