1. An article of manufacture comprising: at least one computer usable medium having computer readable program code logic to execute a machine instruction in a central processing unit, said computer readable program code logic when executing performing the following: obtaining a machine instruction for execution, the machine instruction being defined for computer execution according to a computer architecture, the machine instruction comprising an opcode, a first register field and a second register field; and performing an extract function of an exponent as defined by the opcode of the machine instruction, said exponent stored in a location designated by the second register field, said extract function comprising: expanding at least one value of a datum in decimal floating point format stored in a location designated by the second register field from the decimal floating point format to a working format different from the decimal floating point format, wherein a datum in working format is provided; obtaining a value based on information associated with the datum in working format; and placing that obtained value in a location designated by the first register field.