data egg;
    length SUBID $5 LABTEST $40 LABTESTCODE $8 RESULT $200 UNITS $10;
    input SUBID LABTEST LABTESTCODE RESULT UNITS;
    datalines;
    1011 LEUKOCYTES WBC 5.6 CELLS/MCL
    1012 LEUKOCYTES WBC 4.14 X10^6/UL
    1013 LEUKOCYTES WBC 36.3 %
    1014 LEUKOCYTES WBC 11.4 G/DL
    1015 LEUKOCYTES WBC 480.0 THOUS/MCL
    1016 LEUKOCYTES WBC 19.0 %
    1017 LEUKOCYTES WBC 0.7 %
    1018 LEUKOCYTES WBC 2.8 %
    1019 LEUKOCYTES WBC 10.5 %
    1020 LEUKOCYTES WBC 67.0 %
    ;
run; 

proc fcmp outlib=work.scrambling.test; * Storing functions. Recommended to store in a permanent library for ready access for intended users. ;
    function scramnum (RANSUB) $ ; * Declare a function and declare the type and number of arguments it will receive;
        * Alternatively keyword 'SUBROUTINE' can be used instead of 'FUNCTION' ;
        length TEMPSUB NEWSUB1 $4 COUNT RANSUB Y 8;
        outargs RANSUB;
        * Obtain the number of observations from the input data set ;
        %let DATANAME = %sysfunc(open(egg)); * Use SAS default macros to open the source data set ;
        %let NUM = %sysfunc(attrn(&dataname,nlobs)); * Obtain the Number of observations;
        %let DATACLOSE = %sysfunc(close(&dataname)); * Close the source data set after reading information;
        X = # *Assign number of observations to a variable;

        do i=1 to #
            NEWSUB1=put((RANSUB + 1), 4.);
        end;
        COUNT +1;
        return(NEWSUB1); * Return the processed value to the data set that invoked the function call;
    endsub; * end the subroutine ;
quit;

options cmplib=work.scrambling; * Allows function to be available to the
current library;
* Created data set that will receive scrambled information ;

data scrambled;
    length NEWSUB $4;
    NEWSUB = ' '; * initialize the variable;
    set egg;
    OLDSUB = SUBID *1;
    NEWSUB = scramnum(OLDSUB);
    put NEWSUB=;
run;

data scrambled_egg (rename=NEWSUB=SUBID);
    set scrambled (drop=SUBID);
    drop OLDSUB;
run;