AutoCAD scripting for automated file conversion

We're developing a microfluidic platform for automated blood testing, and we need some help to streamline the design process. The design is created in a PCB routing software and then sent out as a DXF to a contract manufacturer. Specifically, converting the output of the PCB software to the DXF is where we need help. Deliverable: an executable/script for automated conversion of files exported from PCB routing software into DXF. Example tasks in the script would be converting polylines with thickness into an outline of the polyline, or substituting one block for another.