What Jackie said.
Set a Indent style, and do not use repetitive nbsp (repetitive regular spaces get collapsed under HTML rules)
I looked it up for you
For new documents: (On the menu) Styles: edit styles: Paragraph (tab): Adjust indent value: Optionally tick Automatic
For Existing Paragraphs: Right click: Styles: adjust
(have no tested if this works if all (many) paragraphs selected