There's an On Demand PC Studio Fundamentals course available on Bentley Learn:
Filter by AECOsim > PC Studio and you should be able to navigate here:
Also, Bentley user Doug Fitzpatrick wrote up a nice document:
And there's always YouTube... https://www.youtube.com/watch?v=_Zs3wn-gjh8, https://www.youtube.com/watch?v=qNdbTU8G4G8, www.youtube.com/watch , etc.
converted to pdf/cfs-file/__key/communityserver-discussions-components-files/5917/Tutorial_5F00_Custom_5F00_Object_5F00_Bentley.pdf
(Everything very old here - but we still use it:)
something what took us some time to find out: (maybe obvious for every hard core coder ....)
If you want to build an expression to check for a specific / zero value: You have to use == to build the expression. This is not mentioned in any help script.
e.g. IF(\FrameAddTop==0, 10, \FrameAddTop)