Did the Petronas Scholarship specify only Pengetua can certify the copies of documents?
If no, then Guru Kanan can certify without issue.
If yes, then ask the Guru Kanan to certify on behalf of Pengetua. Usually the Guru Kanan should have a stamp that says bp Pengetua but Guru Kanan signs. 'bp' means bagi pihak. Otherwise sometimes I saw manual writing using pen 'bp pengetua', that's fine also.
@Kong please consider sharing your Sunday's interview experience here, thanks in advance!