Append reactive data to specific column('s) row instead of appending starting from first row in googlesheets using append_sheet

Hello, I need to read different values after pressing an action button, and I have multiple action buttons over different pages that i want to repeat( loop over) . My problem is when i try to append the data to the googlesheet, it will append starting from first column row, and i want to specify the column to append the data as am creating dataset.
however, if i want to append different data-frame in the same sheet just different column how do i go about it? i want to store each data in specific column as i loop over the pages. Preformatted text

<!--
server <- function(input, output, session) {
  router$server(input, output, session)
a <- reactive({
   cbind.data.frame(input$name, input$email, Sys.time())
 })
# data1 <- data.frame(a,b)
 observeEvent(input$btn,{
   sheet_append(mysheet, data = a(), sheet = 1)
   if (is_page("/")) {
     change_page("phq_lead")
     delay(3000, change_page("phq1_t"))
   }
  })
-->