You are getting bitten by the fact that the "use" statement is invoked as if it was inside a BEGIN block, so that the assignment:

my $FH_text_W = $main::FH_text_W;
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Occurs before $main::FH_text_W is initialized.

A more traditional perl/OO way to do this would be to make the package "MyPkgDirectory::MyPkg" a true object/class, with a "new" method that initializes the object.

package MyPkgDirectory::MyPkg; # assumes MyPkgDirectory/MyPkg.pm

use strict;
use warnings;
...
sub new{
  my ($classname,$fh) = @_;
  die "File handle not specified" unless $fh;
  return bless {HANDLE => $fh}, $classname;
}
sub samplewrite {
    my ($self,$ver, $sheet) = @_;
   ....
  print {$self->{HANDLE}}  "SHEET $sheet\n"; # Need funny braces to un
+-confuse "print"
}
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Then , in "main:

... # No Pre-declaration. the handle is now a local
  open(my $FH_text_W, $wmode, $filename) or die "ERROR: cannot open $f
+ilename for writing $!";
  my $pkg = MyPkgDirectory::MyPkg::->new( $FH_text_W);

  $pkg->samplewrite(10, "foofoo");
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