The trial is to begin on 11 July.
The moves are seen as part of a crackdown by Pope Francis on clerics and employees of the Church who exploit minors.
Last year, the Pope compared the actions of those who commit such crimes to a "satanic mass".
He also strengthened the Vatican's laws against child abuse.
Wesolowski, who is originally from Poland, was recalled from the Dominican Republic in 2013, after allegations surfaced accusing him of abusing Dominican boys.
He had spent five years in the Caribbean country as the papal envoy.
He was defrocked in June last year after he was found guilty by a Church tribunal - he is the highest-ranking church official to be defrocked for such abuse.
He will now be tried by a Vatican criminal court.
A Vatican statement said the IT systems used by Wesolowski would be scrutinised.
He has been under house arrest in the Vatican since September.
The Vatican said at the time of his arrest that he had not been placed in a police cell because of his poor health.
If found guilty, he could face between six and 10 years in prison.
The Vatican also accepted the resignations of an archbishop in the United States and his deputy following accusations that their archdiocese covered up the sexual abuse of children.
They are Archbishop John Nienstedt and Auxiliary Bishop Lee Anthony Piche from the Archdiocese of St. Paul and Minneapolis.
|John Nienstedt resigned as archbishop on Monday|
Their resignation comes after prosecutors charged their archdiocese with "turning a blind eye" to repeated reports of inappropriate behaviour by a priest who was later convicted of molesting two boys.
Neither man was named in the indictment.
Prosecutors accuse the archdiocese of failing to respond to "numerous and repeated reports of troubling conduct" by Curtis Wehmeyer, a former priest currently serving a five-year prison sentence for molesting two boys.