Thanks for replay.
The problem is basically has place when I try to move Access query to SQL.
Calling procedure fromn another procedure is just one, may be not the best way to do some things with this problem.
In Access query they use Iif() function in order to create a field for example

[SELECT f1,f2,f3,Iif(something,1,0) As Expr]
Iif can contain more than 1 occurences and be very complicated sometimes not readable.
Then use in WHERE statement like Exp1!=.. something.
I have tried to fix that problem using Expr1=CASE ... WHERE... THAN END, but SQl does not give me any chance to reference in my WHERE statement to Expr1 declared field and basically tells me that there is no field like Expr1 exists, which is true.

How I can get it solved?
Which direction to go?
What is the best way?

Thanks in advance.