DOORS DXL: Insert string in XML file on specific location

I try to fill up an XML file. I open the file, and i would like to insert a string into a specific position of the file.

Is there any possibility without reading the whole content, and manipulating the buffer and then overwrite the old file? It is necessary to write a lot of new tags, so i would avoid this method, and write just the new tags directly to their specific position.

Any help is appreciated.

thanks in advance, hb