Here are two ideas.
You can have your path with double quote mark.
export PATH=$PATH:”/C/Program Files (x86)/apache-maven-3.3.3/bin”

Or, You can also make symbolic link for the directory.
ln -s “/C/Program Files (x86)/apache-maven-3.3.3/bin” ./mvnbin
export PATH=$PATH:/your-path/mvnbin

It works for me in mingw32 environment.