Thank you for your suggestions. I found a file named “locale.php” in the “wp-content” folder and I translated it, together with some words and phrases in the theme templates and it looks like it’s exactly what I was looking for. Even easier than working with MO and PO files.
Moşu – deşi aveam o oarece bănuială, nu ştiam că mai sunt şi alţi români pe aici ??