FWIW, I tried to provide the following comments, but LEO sometimes is unresponsive in processing the upload...
What type of comments do you seek? Not very many comments regarding grammar, but the length of this letter makes it difficult to offer any (inline) suggestions.
However, this cover letter seems very long. It's almost an interview and resume in one.
FWIW and IMHO, the following is based on a job ad. Bear in mind that the employees / important persons making the (final) decision / screening candidates often rely on some "secretarry or other clerk" to sort through the applications. Those important persons may not have the time to go through each and every "application."
Therefore, try to minimize text / content and use • bullets to bring forward the key skills sought by the employer. Make it easy to see / read those desired skills you have more conspicuous in the center of the letter.
• 5 years' experience in industry / as a (job title / working with (software apps), etc.....
• Fluent Croatian
• Advanced knowledge of SAP software.
Again, if you have the skills listed in the ad, make them stand out and easy to find in 5 seconds or so glance.
Again, it's most likely some lesser qualified person with little involvement in the selection / hiring process will sort through these letters
Headhunters have told me that "white space" on a cover letter is your friend. When the required skills are buried or are obscure or difficult to find, your "application with resume" can be placed in the wrong pile. You want to go into the "next round / potential candidate" pile.
Your letter is very impressive, but you need to make it easier for the reader to spot your (relevant / applicable) qualifications listed in the ad so they put you (your resume) in the qualified pile.
Also try to see if Frau Knoll exists or is that real person screening applications / the hiring manager. Explore their web site and have some working knowledge of their corporate culture, product line or services, etc. It will help if you land the interview as you discuss your impressive accomplishments stated above.
Hope this is useful but advice from one "LEO" reviewer..