Calculations in case statement

[simma]

Hello,
I have a variable value.Inned something like this

Select col1,col2,@var
from...
where...

The problem is i need to calculate values for @var ,
If col2='A' then @var = col1+10%
else col2='B' then @var=col1-8%

I know I have to use case statemnt but where? In select or where.
Please advice
Thanx

 

[dgaylor]

Select
col1,
col2,
(case when col2 = 'A' then col1 + col1 * .10
when col2 = 'B' then col1 + col1 * (-.08)
else col1) as var

from...
where...

 

[simma]

Thanks dgaylor