>That message indicates that you are using a very old Spreadsheet::Read, as ReadData () accepts (multiple) options since at least 2007 (that is how far my git repo goes back).

I started using Spreadsheet modules 3 or 4 months ago so they can't be old. I even performed upgrade Spreadsheet-Read within ppm and it returned Spreadsheet-Read 0.03: up to date..

Since the module refuses to accept sep parameter (semicolon as separator) I decided to write something by myself. At first I used the Data::Dumper to check what characters I read at all: it reported that characters mentioned below don't map to CP1250. I open a CSV file and use regex to perform replacements: every non-cp1250 character is replaced with unicode character. When I write data into a XLS file using Spreadsheet::WriteExcel the national characters are written correctly.

...

open($fh,"Table.csv");
@Table=<$fh>;
close($fh);

foreach $Table(@Table){
    $Table=~s/\x{00c8}/\x{010c}/g;  # capital C with caron
    $Table=~s/\x{008a}/\x{0160}/g;  # capital S with caron
    $Table=~s/\x{008e}/\x{017e}/g;  # capital Z with caron
    $Table=~s/\x{008a}/\x{010d}/g;  # small c with caron
    $Table=~s/\x{00e8}/\x{0161}/g;  # small s with caron
    $Table=~s/\x{00e8}/\x{017f}/g;  # small z with caron
    
    #    follows the code parsing semicolons 
    
}

# writing data into XLS file
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