You are right. "vorgenommen" is the past participle of "vornehmen", which is one of the seperable verbs. The seperable verbs in German are somewhat special. - in presence and imperfect there are two different forms of the verb depending on wether the verb is used in the main ore in a subordinate clause, - in the past participle the "ge" goes between the seperable prefix and the stem, - the same applies for the "zu" in the infinitive when it is used with "zu". (Unfortunately the comment function does not allow to to write a longer text in a well structured and clear way. Oterhwise I would give you some examples that make it clearer.)