Does the trial version of Stadd have a functional OpenStadd included? Does it have a VBA IDE?
It's impossible to say if the trial version has the OpenSTAAD libraries, because there is no trial page or request form on the official page. I have checked the Bentely website and found out that the Staad.Pro incorporates OpenSTAAD libraries including VBA IDE support.
There is also a page where you can check new additions to the Staad.PRO application: http://communities.bentley.com/products/structural/structural_analysis___design/w/structural_analysis_and_design__wiki/2728.staad-pro-openstaad-solutions
Official page: http://www.bentley.com/sa-IN/Products/STAAD.Pro/
Contact details: http://www.bentley.com/sa-IN/Corporate/Contact+Us/