The Catholic Church cannot forgive ANYTHING; only GOD can do so. And He has promised to do so for anyone who believes that He sent Jesus to die in our place.
For God so loved the world, He gave His only begotten Son, that whosoever believeth in Him should not perish, but have everlasting life". - John 3:16
"Forgive us our trespasses as we forgive those who trespass against us."
In yet another sense, there is a role of the Church in forgiving, since Christ told His disciples on the evening of His resurrection, "Whose sins you shall forgive, they are forgiven them; whose sins you shall retain, they are retained."
Whose sins YOU shall forgive; whose sins YOU shall retain.
That's what He said to His disciples after He breathed on them and said, "Receive the Holy Spirit." In other words, He was talking to His gathered church.