For npm scripts, NPM supports env variables in the form $npm_package_config_var, for example. This can be used in npm run commands. However, this is platform specific. Windows uses %var% where *nix uses $var. This tool can be run like:
compat "ncp $sourcePath $destPath"
so that, on windows platforms, the following command will be run:
ncp %sourcePath% %destPath%
It will also allow relative paths to be used in the command on windows (arguments will be left alone as they generally work with either forward or back slashes):
compat '../../node_modules/.bin/browserify index.js -s JID -o bundle.js'
=>
....\node_modules.bin\browserify index.js -s JID -o bundle.js