VBScript doesn't provide implicit parent objects like the VBA runtime environment does, so you need to make everything explicit:
Set xl = CreateObject("Excel.Application")
Set wb = xl.Workbooks.Add
Set ws = wb.Sheets(1)
ws.Columns("A:A").Select
...
Also, VBScript doesn't recognize VBA named constants, so you need to either use the numeric value:
...
xl.Selection.SpecialCells(4).Select
...
or define the constant in your script:
Const xlCellTypeBlanks = 4
...
xl.Selection.SpecialCells(xlCellTypeBlanks).Select
...
See here for more information about translating VBA to VBScript.