Regulating Voltage with LM78XX

I have a project that requires 12V. I have some LM7815's and looked at the Fairchild pdf *** and I need some help understanding the formula to specify 12 Volt out. (maybe that can't be done)?
------------------
in 18V------o-- 1 -| |- 3 ---o--------o- output
| | LM78XX | | > ^ ^
| ------------------ | < | Vxx
--- | 2 --- R1 > | |
c1 --- 0.33uF | | Co --- 0.1uF | | |
| | | | | | |
| Iq | | | | | v --- Io
|------------v--0-----------------o-----------|-----| |
| v
Vxx > /
Io = ----- +Iq RL </
R1 >
/<
/ |
GND

The only thing I know is R1 = 220 (I have these).
What is Iq/lq and Io/lo? You can see I am no good in math. I was a programmer and If I know the formula and meanings of I? I could write a program and let the computer do it. Most programmers are dumber than Dog S!@# in math and anything not(simple minded) me, anyway. KISS is my motto.

While I'm here, this circuit is supposed to switch a 12V relay after being on for 2 hrs, for 120V on/off and I was wondering how to use the 120V instead of buying a transformer like 120/18V or whatever? to drive the relay.
Any Help is appreciated;
Thanks, Don Bauer
.

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