needing excel function

i need a function that remove some parts of a paragraph, its final and the firsts lines according to this: 1)eliminate its final: given a string, search that string into text and eliminate all the rest from that string. 2)eliminate the firsts lines, given the "n" number of text strings eliminate the first "n" of text rows ----------------------------------------------------------------EXAMPLE---------------------------------------- here the text: William Shakespeare From Wikipedia, the free encyclopedia Shakespeare was born and brought up in Stratford-upon-Avon, Warwickshire. At the age of 18, he married Anne Hathaway, with whom he had three children: Susanna and twins Hamnet and Judith. Some time between 1585 and 1592, he began a successful career in London as an actor, writer, and part-owner of a playing company called the Lord Chamberlain's Men, later known as the King's Men. At age 49 around 1613, he appears to have retired to Stratford, where he died three years later. Few records of Shakespeare's private life survive, which has stimulated considerable speculation about such matters as his physical appearance, sexuality, religious beliefs and whether the works attributed to him were written by others.[8][9][10] These speculations are often criticized for failing to point out the fact that few records survive of most commoners of his period. 1) to eliminate from the substring "strat" 2)to eliminate the first 3 lines with text the results were: At the age of 18, he married Anne Hathaway, with whom he had three children: Susanna and twins Hamnet and Judith. Some time between 1585 and 1592, he began a successful career in London as an actor, writer, and part-owner of a playing company called the Lord Chamberlain's Men, later known as the King's Men. At age 49 around 1613, he appears to have retired to Strat as you can see i have removed the last part and the first 3 lines with text