Masken, minor update to maciep's code.

It does appear to work even with binary files in the folder.

I added line to show which file contains the entry. But seems to find the length of numbers anywhere in the file as you requested.

Nice job maciep.

Code:
Dim $theDir, $txtFile, $, $line, $j, $possibleNumber
$theDir = 'c:\numtest\'
$txtFile = dir($theDir + '*.*')
while @error = 0
   $ = open(1,$theDir + $txtFile)
   $line = readline(1)
   While @error = 0
      for $j = 1 to len($line)-7
         $possibleNumber = substr($line,$j,7)
         if $possibleNumber = 0.0 + $possibleNumber
            ? $txtFile + ' ' + $possibleNumber
         endif
      next
      $line = readline(1)
   loop
   $ = close(1)
   $txtFile = dir()
loop