What is seen to actually occur if a female were to be the subject of laying on of the hands in ordinations, according to the Catholic Church?
The short answer is nothing.
The woman in question is not ordained, even after going through the motions of an ordination.
Pope John Paul II in his Apostolic Letter Ordinatio Sacerdotalis is very clear on the matter.
Priestly ordination, which hands on the office entrusted by Christ to his Apostles of teaching, sanctifying and governing the faithful, has in the Catholic Church from the beginning always been reserved to men alone. This tradition has also been faithfully maintained by the Oriental Churches.
Furthermore, the fact that the Blessed Virgin Mary, Mother of God and Mother of the Church, received neither the mission proper to the Apostles nor the ministerial priesthood clearly shows that the non-admission of women to priestly ordination cannot mean that women are of lesser dignity, nor can it be construed as discrimination against them. Rather, it is to be seen as the faithful observance of a plan to be ascribed to the wisdom of the Lord of the universe.
Although the teaching that priestly ordination is to be reserved to men alone has been preserved by the constant and universal Tradition of the Church and firmly taught by the Magisterium in its more recent documents, at the present time in some places it is nonetheless considered still open to debate, or the Church's judgment that women are not to be admitted to ordination is considered to have a merely disciplinary force.
Wherefore, in order that all doubt may be removed regarding a matter of great importance, a matter which pertains to the Church's divine constitution itself, in virtue of my ministry of confirming the brethren (cf. Lk 22:32) I declare that the Church has no authority whatsoever to confer priestly ordination on women and that this judgment is to be definitively held by all the Church's faithful.
Thus we see that the ordination of women to the priesthood is not a question or mere Church discipline, but rather that the Church has no true authority (power) from Christ to admit women to Sacred Orders.
In the Catholic Church, a bishop is latae sententiae excommunicated if he attempts to confer Holy Orders on a woman, alongside the woman who attempted to receive the consecration.
The "ordination" of a woman to the Sacrament of Holy Orders is prohibited by the Catholic Church. An ordination like this carries automatic excommunication for the person who performs the "ordination" as well as the person who is "ordained."
"It is important for Catholics to understand that they cannot receive a valid Sacrament such as Baptism, Confession or Eucharist from an excommunicated person. Catholics should never attend a so-called Mass in which an excommunicated person is presiding.
Canon Law states that only baptized male alone receives sacred ordination validly (Canon 1024).