The function add a wml string into the document after, before or on a cursor location.
This function will be deprecated in the next release because it is not
efficient and make users write complex code. Use instead fpar()
to build
formatted paragraphs.
slip_in_xml(x, str, pos)
an rdocx object
a wml string
where to add the new element relative to the cursor, "after" or "before".