I think the only way to do this without GDL is to use the Grasshopper-ARCHICAD Connection. For that you will need Rhinoceros, which costs money (money well spent in my opinion), the Grasshopper Add-On is free with Rhino.
Then you will be able to create visual scripts (no programming) and those visual scripts will place ARCHICAD construction elements like Walls, Slabs, etc.
The cool thing about that is that there are sliders on which you can set input parameters and as you change a value on the slider the resulting geometry is updated in real time. So it is very fast to find the exact input parameters you want to use.