arabicNumeral = 1990
ConvertToRoman()
TextWindow.WriteLine(romanNumeral) 'MCMXC
arabicNumeral = 2018
ConvertToRoman()
TextWindow.WriteLine(romanNumeral) 'MMXVIII
arabicNumeral = 3888
ConvertToRoman()
TextWindow.WriteLine(romanNumeral) 'MMMDCCCLXXXVIII

Sub ConvertToRoman
  weights[0] = 1000
  weights[1] =  900
  weights[2] =  500
  weights[3] =  400
  weights[4] =  100
  weights[5] =   90
  weights[6] =   50
  weights[7] =   40
  weights[8] =   10
  weights[9] =    9
  weights[10] =   5
  weights[11] =   4
  weights[12] =   1
  symbols[0] = "M"
  symbols[1] = "CM"
  symbols[2] = "D"
  symbols[3] = "CD"
  symbols[4] = "C"
  symbols[5] = "XC"
  symbols[6] = "L"
  symbols[7] = "XL"
  symbols[8] = "X"
  symbols[9] = "IX"
  symbols[10] = "V"
  symbols[11] = "IV"
  symbols[12] = "I"
  romanNumeral = ""
  i = 0
  While (i <= 12) And (arabicNumeral > 0)
    While arabicNumeral >= weights[i]
      romanNumeral = Text.Append(romanNumeral, symbols[i])
      arabicNumeral = arabicNumeral - weights[i]
    EndWhile
    i = i + 1
  EndWhile
EndSub