After a couple of days struggling I found the solution:
Just create desired style in stylebook and add items to ListBoxItem as this
Pay attention to instantiating from TListBoxItem
Itemx := TListBoxItem.Create(self);
Itemx.StyleLookup := 'listBoxItemNumericEditable';
Itemx.Text := 'A Title';
Here is the trick
Itemx.StylesData['nmbLeft.Value'] := 50;
Also you can even add event handler like this
Itemx.StylesData['nmbLeft.OnChange'] := TValue.From<TNotifyEvent>(DoNumberChange);