If this is the general format of the lines you need to extract data from, it appears what you're looking for is just the third field delimited by whitespace. This should work:

my $string = "USD_ABD DOLARI                608,132   611,064   607,70
+6   611,981   1.0      1.0";
my $value = (split /\s+/, $string)[2];
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Which leaves $value with 608,132.