c:\@Work\Perl>perl -wMstrict -le
"my $v = {
   R3R3_foo_IF => 'xyzzy',
   R3R3_bar_IF => 'wibble',
   };
 ;;
 my $pic = 'foo';
 ;;
 print qq{whatever $v->{ qq{R3R3_${pic}_IF} } and so on};
"
whatever xyzzy and so on