1. A method of automatically invoking a program or system function on a computer system comprising the steps of: receiving a user-selected first insertion point or replacement area within a first user interface to a destination computer file; subsequent to receiving said first insertion point within a destination file, providing a second user interface to content of a source computer file upon user command; subsequent to providing said second user interface to said source file, responsive to a user highlighting text within said second user interface of an application program on a computer display, automatically copying said highlighted text from said application program to a clipboard buffer, wherein said application program comprises an application program selected from a group of a word processor, a spreadsheet, a contact management utility, an electronic address book, an electronic calendar, an email client, a presentation program, a financial program, and a bookkeeping program; searching a plurality of auto-trigger rules for a rule which correlates to said highlighted text copied to said clipboard; and upon finding a correlating rule, invoking one or more programs or system functions according to said found rule without need to modify or change said application program.