drupal php script -- 2

Hi, I have a small task to begin. - I have a taxonomy vocabulary with parents and children: term1 - subterm1 - subterm2 - subterm3 term2 - subterm4 - subterm5 - subterm6 term3 - subterm7 - subterm8 - subterm9 - I have a node type with a term reference field. - The script has to bee included in a node tpl file. I need a php script which does the following: [children of term1 if exists] > [children of term2 if exists] > [children of term3 if exists] - ordered by term weight Examples subterm2 > subterm4 > subterm8 or subterm2 > subterm4,subterm5 > subterm7