Drop down navigation menus

Hi fellow Pressers,
I have created an additional site to host my podcasts using WordPress. My main site https://www.matthewholden.com.au links to my podcast site https://www.matthewholden.com.au/podasia/ which has the Word Press as the master page.

What I want to do is modify the theme of the default wordpress layout (or use another appropriate layout from the loads on offer) but I also need to include my drop down navigation script which – for brevity – I include a snippet here:

<!– #BeginLibraryItem “/Library/nav menu-v01.lbi” –>
<script type=”text/javascript” language=”JavaScript1.2″ src=”/Library/stm31.js”></script>
<script id=”Sothink Widgets:nav menu-v016.pgt” type=”text/javascript” language=”JavaScript1.2″>
<!–Navigation menu button v1.04 16-MAR-2005 –>
<!–Navigation menu button v1.04 27-APR-2005 –>
<!–
stm_bm([“tubtehr”,430,””,”blank.gif”,0,””,””,0,0,250,0,1000,1,0,0,””,””,0],this);
stm_sc(1,[“#fffff7″,”#b5bed6″,””,””,3,3,0,0,”#a3a39d #ffffff #ffffff #a3a39d”,”#000000″,”up_disabled.gif”,”up_enabled.gif”,-1,-1,0,”down_disabled.gif”,”down_enabled.gif”,-1,-1,0]);
stm_bp(“p0″,[0,4,0,0,1,2,0,0,100,””,-2,””,-2,90,0,0,”#000000″,”#000066″,””,3,0,0,”#ffffff”]);
stm_ai(“p0i0″,[0,”Home”,””,””,-1,-1,0,”https://www.matthewholden.com.au/index.htm&#8221;,”_self”,””,”Return to the Home Page”,””,””,0,0,0,””,””,0,0,0,0,1,”#000066″,0,”#cccccc”,0,””,””,3,3,0,0,”#ffffff”,”#ffffff”,”#ffffff”,”#000066″,”bold 8pt Arial”,”bold 8pt Arial”,0,0]);
stm_aix(“p0i1″,”p0i0″,[0,” University “,””,””,-1,-1,0,”https://www.matthewholden.com.au/university.htm&#8221;,”_self”,””,”University research and teaching materials”]);

My questions are:
1. What file do I modify and attempt to insert the completed menu code?
2. Where in the appropriate file do you insert such menu code? This is not PHP so how can I avoid having errors and conflicts.

Many thanks.

Matthew