NUMBERVALUE

Convert text to number, in a locale-independent way.

Constraints: LEN(decimal_separator) = 1, decimal_separator shall not appear in group_separator

This function is available since LibreOffice 4.1.

NUMBERVALUE("Text" [;decimal_separator [;group_separator]])

Text is a valid number expression and must be entered with quotation marks.

decimal_separator (optional) defines the character used as the decimal separator.

group_separator (optional) defines the character(s) used as the group separator.

=NUMBERVALUE("123.456";".";",") yields 123.456