awk extract certain digits from file with index substr

I would like to extract a digit from $0 starting 2,30 to 3,99 or 2.30 to 3.99

Can somebody fix this?

awk --re-interval  '{if($0 ~ /[2-3]{1}[,.][0-9]{2}/) {print FILENAME, substr($0,index($0,/[2-3]{1}[,.][0-9]{2}/) , 4)}}'

input
abcdefg sdlfkj 3,29 g. lasdfj
alsdfjasl 2.86 gr. slkjds sldkd
lskdjfsl sdfkj kdjlksj 3,34 g sldkfj
...

Does it have to be AWK? Is Perl acceptable?

Don't have perl on my system.

nawk '{
  for(i=1;i<=NF;i++)
    if ($i ~ "^[2-3][.,][0-9][0-9]$" && $i>=2.30 && $i<=3.99)
          print $i
}' myFile

INDEED! Thanks!