I found a great resource: Convert VBA to OpenOffice Basic
While much of the underlying logic behind OpenOffice Basic compares to that of Visual Basic for Applications, there exists fundamental differences to the way the code is constructed. This Excel VBA to OpenOffice Basic converter offers a starting point for migrating VBA projects in Excel to the OpenOffice or Star Office Calc application. The converter may also serve as a learning mechanism to better understand the similarities and differences between the VBA and OO Basic coding specifications.
Of course this applies to LibreOffice too. They have a form where you can drop in a line of vba code and it will offer the nearest OO equivalent.
They have been added to my links as well.