When dealing with dates it is often easier to actually use a SAS date valued variable an a format. Your request for / in the middle of the date with the month name is uncommon but doable with a custom format.
The following code creates a SAS date valued variable from a character variable that I think mimics your fechapa variable.
Then uses the custom format created with proc format to display the date as desired.
NOTE: the case of the letters in the string '%d/%b/%Y' is critical as changing the Y to y will result in a 2 digit year and a %B instead of %b is the full name not the 3-letter abbreviation. The % tells proc format the values are directives and the datatype tells SAS what ranges of values to expect.
data example;
x='20160425';
y=input(x,yymmdd8.);
format y date9.;
run;
proc format library=work;
picture DateSlash (default=12)
low-high= '%d/%b/%Y' ( datatype=date)
;
run;
proc print data=example;
var y;
format y dateslash.;
run;
So once you have your Date variable you use the format dateslash as needed. Note, since this is a custom format permanent association of the format means that you should place the format in a location that is always in the FMTSEARCH path OR rerun the proc format as needed.
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