How to save word document into HTML file using C#

I have word document with table, table has multiple row .and that row contains nested unordered list like following format .

o 1.2

1.2.1
1.2.2

but when i save that word document in html format then nested list not generated properly

What I have tried:

objDoc.SaveAs(ref fileNameHTML, ref fileFormat, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown, ref unKnown);

Also i have try

object szDocFormatNew = 10;

objDoc.SaveAs(ref fileNameHTML,ref szDocFormatNew);

Please help me to sort out my problems.