./leg.pl `mineng.pl |grep "This was in file"|awk '{print $5}'`

##</code><code>##

my $minfilename = shift; # = $ARGV[0];
:
:
#somewhere in the loop:
if($f eq $minfilename){
 #store values to substract them later
}

##</code><code>##

my $minfilename = `grep "This was in file" min.txt|awk '{print $5}'`;