GenerateAfter can help here.

///do ##class(Test.GenerateHelper).Generated()
///Hi there!
Class Test.GenerateHelper
{
  ClassMethod Generated() [ CodeMode = objectgenerator, GenerateAfter = Helper ]
  {
    set text = ..Helper()
    do %code.WriteLine(" write """ _ text _ """")
  }

  ClassMethod Helper() As %String
  {
    return "Hi there!"
  }
}

Is it a ZEN Select component rather than just an html select?   If so, maybe set the displaylist and value via the ZEN helpers? 
From memory (and it has been a long time), something like:
var select = zen(zenIdOfSelect)
select.diplayList='one,two,three'
select.setValue(3)
select.refreshContents()