SAS Data Sets Manipulations

Hello, I am having problem with step #2 of my program. I am not sure if I can just use "rename" statement when I am storing records from "Var4" to "Var6" or I have to use something else? The thing is that I still have to unduplicate "TpData" SAS dataset by "Var4" in the step #4.

1. Create a temporary SAS dataset ("TpData") from already existed SAS dataset ("lib.Data1"), then
2. Get total of records in each "Var4"variable and store in "Var6" variable
3. Create "Var1Var2" variable from already existed variables ("Var1" and "Var2") in "lib.Data1" dataset with the following options:
  if "Var1" = 12 and "Var2" = 211 then set "Var1Var2" = 12211
  else set "Var1Var2" = concatenation of "Var1" and "Var2"
4. Unduplicate "TpData" dataset by "Var3" and "Var4"
5. Keep only "Var1", Var2", "Var3", "Var6", and "Var1Var2" variables in the "TpData" dataset


data TpData (keep=Var1 Var2  Var3 Var6 Var1Var2           /*** 1 and 5 ***/
                     rename=(Var4=Var6));                                              /*** 2 ***/
set lib.Data1;
   length Var1Var2  $6.;
 
 if Var1=12 and Var2=211 then                             /*** 3 ***/            
    Var1Var2="12211";
  else Var1Var2 = trim(left(PUT(Var1, $3.))) || trim(left(PUT(Var2, $3.)));  
 run;

PROC SORT data=TpData NODUPKEY;                 /*** 4 ***/
  by Var3 Var4;                                            
run;