options ls=95  nodate;
data diets;
   length trt $19.;
   input trt $ wtgain;
   cards; 
Control 4.1
Control 3.3
Control 3.1
Control 4.2
Control 3.6
Control 4.4
Control+level-1-A 5.2
Control+level-1-A 4.8
Control+level-1-A 4.5
Control+level-1-A 6.8
Control+level-1-A 5.5
Control+level-1-A 6.2
Control+level-2-A 6.3
Control+level-2-A 6.5
Control+level-2-A 7.2
Control+level-2-A 7.4
Control+level-2-A 7.8
Control+level-2-A 6.7
Control+level-1-B 6.5
Control+level-1-B 6.8
Control+level-1-B 7.3
Control+level-1-B 7.5
Control+level-1-B 6.9
Control+level-1-B 7
Control+level-2-B 9.5
Control+level-2-B 9.6
Control+level-2-B 9.2
Control+level-2-B 9.1
Control+level-2-B 9.8
Control+level-2-B 9.1
run;
proc glm;
   class trt; /*watch ordering in CLASS LEVEL INFO in output*/
   model wtgain=trt;
   contrast "theta_a:control - avg(others)" trt 4 -1 -1 -1 -1;
   contrast "theta_b:(A-B)_1 - (A-B)_2" trt 0 1 -1 -1 1;
   contrast "theta_c:A-B" trt 0 1 -1 1 -1;
   contrast "theta_c:1-2" trt 0 1 1 -1 -1;
run;

data diets;
   set diets;
   control=(trt="Control"); 
   if (control=0) then do;
      additive=(substr(trt,17,1));   
      amount=(substr(trt,15,1));
/* SUBSTR plucks the 15th char from the string and writes it to "amount"*/
   end;
   else do;
      additive="n";
      amount="n";
   end;
run;
proc glm;
   class control additive amount;
   model wtgain=control additive(control) amount(control) additive*amount(control) ;
   lsmeans additive*amount(control);
run;