Hi Domagoj,
i had similar request and this was the solution.
in home.htmpl define JS function
function myCreate(id, pcat)
{
if(typeof ahdtop.ticketObj == "object")
ahdtop.ticketObj.resetTicket();
var url=cfgCgi+
"?SID="+cfgSID+
"+FID="+fid_generator()+
"+OP=CREATE_NEW+FACTORY="+pcat+"+PRESET=category:pcat:" + id;
window.location=url;
}
and in link part reference it like this
<td style="padding-left: 15px;">
<a href="javascript: myCreate('402115','cr');"
class="emp portlet_body_text"
onmouseover='window.status = "Create a new Request"; return true;'
onmouseout="window.status = window.defaultStatus; return true;">LABEL FOR CATEGORY</a>
</td>
where 402115 is id of category in prob_ctg table
hope it helps you