Changing ListItem index

Is it possible to change the index of a ListItem? For example,

<List>
  <ListItem Index=1>
    <Paragraph>A</Paragraph>
  </ListItem>
  <ListItem Index=3>
    <Paragraph>C</Paragraph>
  </ListItem>
</List>

<List>
  <ListItem Index=1>
    <Paragraph>A</Paragraph>
  </ListItem>
  <ListItem Index=3>
    <Paragraph>C</Paragraph>
  </ListItem>
</List>

Result:

1. A
3. C

1. A
3. C

Changing ListItem index - C#