Drop variables from comparison using a macro

[bharath86]

%let lpremig=;
%let lpostmig=;

libname premig "&lpremig";
libname postmig "&lpostmig";
option nodate pageno=1 linesize=80 pagesize=40;

%macro Compds (dsview);
Proc sort data=premig.&dsview out= &dsview.pre;
By id;
Run;

Proc sort data=postmig.&dsview  out=&dsview.post;
By id;
Run;

Proc compare base=&dsview.pre compare=&dsview.post (drop=a b c d e f g) ; 
run;

 %mend compds;

 %compds(A);
 %compds(B);

I am trying to eliminate a few variables from a comparison in the above macro, however, the variables in the drop statement are not available in all datasets. 

If need to run both A and B reports together and eliminate a few variables without an

ERROR: The variable b c in the DROP, KEEP, or RENAME list has never been
referenced.

I dont want to change the variable names every now and then since I know I have a set of variables to be eliminated from few datasets. 

I need a single report with all datasets comparison by eliminating the set of variables where ever applicable. 

Please advise, how to achieve this. 

[Astounding · Accepted solution]

Take a look at the global option DKRICOND=

[bharath86]

Excellent, learned something new today.