putting data into character variable sas

I'm facing the problem that I want to put data into a character variable. So I have a long tranposed dataset where I have three variables: date( by which i transposed before hand) var (has three different outputs of my previous variables) and col1 (which includes the values of my previous variables). Now i want to create a forth variable which has as well three different outputs. My problem is that I can create the variable put with my code it does always create missing value.

data pair2;
 set data1;
if var="BNNESR" or var="BNNESR_r" or var="BNNESR_t" then output;
length all $ 20;
all=" ";
if var="BNNESR" then all="pdev";
if var="BNNESR_t" then all="trigger"; 
if var="BNNESR_r" then all="rdev";
drop var;
run;

Afterwards I want to tranpose it back by the "all" variable. I know i could just rename the old vars before I transpose it and then just keep them. But the complete calculation will go on and actually will be turned into a macro where it is not that easy if would do it like that way.