r - How can I provide a location in R shiny where the submitted file should be saved?

Question

The code below takes the user's input file (filename1) and uploads it to the same directory with a new name (example: userFile_filename1) in the same directory. I'd want to upload the input file to a separate location. In R shiny, how can I set a path of my choice?

library(shiny) 

ui <- shinyUI(fluidPage(

  sidebarLayout(
    sidebarPanel(
      fileInput('file1', 'Select file to upload' )  
    ),
    mainPanel(
        h4('List of uploaded files:')
       ,verbatimTextOutput('fileList')
    )
  ))
)

server <- shinyServer(function(input, output) {

        observe({  
          if (is.null(input$file1) ) {    return(NULL)  }  
          file.copy(from = input$file1$datapath, to =  paste0('userFile_',input$file1$name )  ) 
        }) 

        output$fileList <- renderText({  
          input$file1
          dir(pattern = 'userFile_') 
        })
})

shinyApp(ui, server)