How to mask specified number of integers ex:- ######7890.

a!localVariables(
  local!text: "9876543210",
  local!numberOfChars: 7,
  local!textToReplace: left(local!text,local!numberOfChars),
  local!replacingValue: joinarray(repeat(local!numberOfChars,"#")),
  substitute(local!text,local!textToReplace,local!replacingValue)
)

a!localVariables(
  local!text: "9876543210",
  local!numberOfChars: 6,
  rept("#", local!numberOfChars) & mid(local!text, local!numberOfChars + 1, 100)
)