nginx/plesk, nodejs+apache - rooting

facts:
-ubuntu
-plesk 11.0.9
-node.js/apache
-nginx

i want to run node/apache on the same server,
so i thought nginx wld be the right way

so i installed nginx via plesk

the problem is that i dont find any fitting tutorial/ i don't even know which data to edit to get the problem solved

the setting should be easy -

subdomA.dom.com => apache
subdomB.dom.com => node

so i just need a simple if or whatever that changes the port either to apache or to node

sth like

if(subdom)
    if(subdomA)
         changePort 1111 (apache)
    else if(subdomB)
         changePort 2222 (node)
else
   changePort 1111 (apache)

Solution