How To return String of value from String of column name?

[lpf19sam]

I am using VERSION 7.15. I set a string without quotation mark around, I wonder How to convert the string into a string that have quotation mark around and could be as a value, not a column name

it is worked when directly add the quotation mark around;

%let string = 'test';

data test_table;
x =&string;
y = 5;
run;

I want to adjust the test into 'test' so that I am able to run the below code.

%let string = test;

/*(some code in here to change the value test from column name to string value)*/

data test_table;
x =&string;
y = 5;
run;

Thanks!

[Astounding · Accepted solution]

If I understand correctly, you can use double quotes:

x = "&string";

[lpf19sam]

OMG it worked...Thanks so much! should have posted the question 3 hours earlier..