[opensuse-buildservice] removing one line from a predefined multiline RPM macro

Hello! What is the smartest way to remove one specific line from a predefined RPM macro if it is present? Example: Consider the predefined macro %{amacro} contains: foo bar otherline Now I want to remove the line with "bar" (or make it an empty line) but leave all other content untouched. This is where macro expansion mechanisms become an ugly beast... :-/ Robert -- Robert Schiele Dipl.-Wirtsch.informatiker mailto:rschiele@gmail.com "Quidquid latine dictum sit, altum sonatur."