How can I pick test case property inside a command line

For example, this is the snippet

def foldername = context.expand( '${#TestCase#folderName}' )

def cmd='"aws s3 cp s3://<bucketName>/<folder>/' +foldername.toString()  '<folderPathtoCopy>/' + foldername.toString()' --recursive"'
def command='"C:/Program Files/Git/git-bash.exe" -c '+cmd
def proc = command.execute()
proc.waitForOrKill(100000)

I want to download a folder from S3 which is upload by the foldername stored in test case property. foldername changes dynamically. I know there is some syntax errors but not able to solve it