The PDAL PCD Writer can write .pcd files. For it to work, you must have linked the PCL libraries at compile time. The PDAL OSGeo4W build does not have PCL support. If you are unable to build PDAL with PCL support yourself, one possibility is to use PDAL's Docker containers to achieve your task -- those have PCL linked.
Then, simply run
Using your own PDAL build with PCL linked:
pdal translate input.las output.pcd
docker run -v /c/Users/hobu/:/data pdal/pdal:1.5 ^
pdal translate /data/input.las /data/output.pcd