CMAQ downscale problem

HI, everyone.
I am new to CMAQ. I found that the input data from test cases and other dataset are always from WRF mode. If I want to do my own simulation, can I just use CMAQ ready input file and modify them to a smaller domain I am interested in?

CMAQ requires meteorological input data in the form produced by MCIP. Currently, WRF is the only meteorological model that MCIP can handle directly.

“Smaller domain” can either mean fewer grid cells (a subset of the parent domain) or can mean a nested domain consisting of smaller (higher-resolution) grid cells. Either way, you need meteorological input data for the new CMAQ domain. This includes boundary conditions, so it is not possible simply to window all existing MCIP outputs for one domain and run on another.

Thanks for your reply. I am trying to use WRF now