SAS Macro quoting issues -

i trying perform operations on binary data saved macro variable. datastep below saves data macro variable without issues:

data _null_;   infile datalines truncover ;   attrib x length=$300 informat=$300. format=$300.;   input x $300.;   put x=;   call symput ('str',cats(x));   datalines4; ‰png  >     ihdr   )   )   ëŠz   srgb ®Î=é   gama  ±^üa    phys  ;à  ;ÃÇo¨d   zidat8oåŒ[ À½ÿ¥Ó¼”Ö5dˆ_v@aw|+¸anŠ‡;6<ÞórÆÒÈefõu/'“#f™Ù÷&É|&t"<ß}4¯à6†Ë-Œ_È(%<É'™ènß%)˜Î{-    iend®b`‚ ;;;; run; 

when try , use contents of macro variable in way, combinations of reserved characters making impossible work with. following reserved characters in value, , not matched:

&%'"() 

i've tried every combination of macro quoting functions can think of , can't value print using %put():

%put %nrbquote(&str); 

results in:

symbolgen:  macro variable str resolves ‰png  >     ihdr   )   )   ëŠz   srgb ®Î=é   gama             ±^üa    phys  ;à  ;ÃÇo¨d   zidat8oåŒ[             À½ÿ¥Ó¼”Ö5dˆ_v@aw|+¸anŠ‡;6<ÞórÆÒÈefõu/'“#f™Ù÷&É|&t"<ß}4¯à6†Ë-Œ_È(%<É'™ènß%)˜Î{-             iend®b`‚ error: value É not valid sas name. error: sas macro facility has encountered i/o error.  canceling submitted statements.  note: sas system stopped processing due receiving cancel request. 

ultimately, i'd convert these values base64 encoding using following statement (i've pre-calculated length of base64 format ease-of-debugging):

%let base64_string = %sysfunc(putc(%nrbquote(&str),$base64x244.)); 

you can use %superq() quote macro variable without having first expand it. note takes name of macro variable , not value argument.

%let base64_string = %sysfunc(putc(%superq(str),$base64x244.)); 

but why not transformation in data step , avoid macro quoting issues?