Turn on the macro recorder (Tools | Macro Record new macro...),
select the first cell in column C with data in column B. Suppose it is
C1. Enter the untested formul
=IF(OR(B1<20,B1200),5,IF(B1<=30,0.1,0.2))
Move the mouse to the lower right corner of the cell (it will become a
black cross) and double-click. This will copy the formula as far down
column C as there is data in B.

If you don't want to leave the formula in place, select column C, copy,
right-click, select Paste Special... | Values.

Turn off the recorder and XL will give you the necessary code.

You may also want to see
Beyond Excel's recorder
http://www.tushar-
mehta.com/excel/vba/beyond_the_macro_recorder/index.htm#eg4

particular Example 4: Add a formula to a range of cells

--
Regards,

Tushar Mehta
www.tushar-mehta.com
Excel, PowerPoint, and VBA add-ins, tutorials
Custom MS Office productivity solutions

In article .com,
says...
Hi I need to write a macro that I believe is pretty easy but I'm a
little rusty on my programming. Any help would be greatly appreciated.

I have a list like this:
name1 25
name2 50
name3 70
etc

I need to go down the numbers column (column B). If the number is
between 20 and 30, I want to insert ".1" in a third column on the
right. If the number is between 30 and 100, I want to insert ".2".
else, I want to insert "5".

Thanks in advance!