Hi:
It seems to me that you do not want a DETAIL report (where you see 1 report row for every observation in the original input data). You describe a SUMMARY report (where every report row represents the information for a group of observations).
SAS has many, many summary-level procedures: PROC SQL, PROC MEANS, PROC TABULATE, PROC REPORT.
Depending on what you want to do (generate output dataset or generate an HTML, RTF or PDF report), you might try starting with PROC MEANS and then graduate to TABULATE or REPORT if MEANS isn't what you want.
cynthia
[pre]
ods html file='c:\temp\examp_means.html' style=sasweb;
proc means data=x sum maxdec=0;
var a b;
run;
ods html close;
[/pre]