  Parametric Computer-aided design (CAD) enables the creation of reusable
models by integrating variables into geometric properties, facilitating
customization without a complete redesign. However, creating parametric designs
in programming-based CAD presents significant challenges. Users define models
in a code editor using a programming language, with the application generating
a visual representation in a viewport. This process involves complex
programming and arithmetic expressions to describe geometric properties,
linking various object properties to create parametric designs. Unfortunately,
these applications lack assistance, making the process unnecessarily demanding.
We propose a solution that allows users to retrieve parametric expressions from
the visual representation for reuse in the code, streamlining the design
process. We demonstrated this concept through a proof-of-concept implemented in
the programming-based CAD application, OpenSCAD, and conducted an experiment
with 11 users. Our findings suggest that this solution could significantly
reduce design errors, improve interactivity and engagement in the design
process, and lower the entry barrier for newcomers by reducing the mathematical
skills typically required in programming-based CAD applications
