There's a prog called Aquarius Macro Extractor (search for Macro_extr_s2a-v01.zip)

It was intended for FS98/2000 but I've used it with SCASM type scenery from later versions.

It's tricky to use and frankly although I've managed to extract one or 2 macros from sceneries, I've never managed to get anything of any real value that I could use that I couldn't make quicker and better myself in EOD.

As far as I know this is the only SCASM type extractor.

FS2004 has moved to XML scenery. There are tools to extract items from default scenery but I'm afraid I can't tell you anything about them.