Find a node in a phrase. There are two variants: to find a node in a phrase aPhrase by the node's name nameString and to find a node in a phrase aPhrase by node number positionNum.
returnedConcept = findnode(aPhrase, nameString);
returnedConcept - type: con
aPhrase - type: phr
nameString - type: str
returnedConcept = findnode(aPhrase, positionNum);
returnedConcept - type: con
aPhrase - type: phr
positionNum - type: int