What I understood from your question is that when the you create a numbered list and want to change its' direction to RTL, the content probably looked something like ( نص عربيl4. ) as the number 14 is touching the text instead of having the dot as a separator. If that's your case then try this:
1.Simply highlight the text you want to change its' direction.
2.right click to bring the options menu
3.Choose the paragraph option
4.in the first page in the general section, choose the direction of the text "right-to-left".
The highlighted lines will change, It's possible to show bullet points from the same list in different directions but I don't think you can split a text from the same line and show each part in a different direction.