Try starting from 1. Unfortunately VB/VBA/VBS and its other technologies like WMI/ADSI are not very standard on where to start the array index.
btw, you don't have to put step 1 .. its implied
The best way to do this is to create a control array, but not sure if you can do that in POS access.
You can try, by selecting one of your text boxes, and copying and pasting onto the same form. It should prompt you if you want to create a control array IF its possilbe.
If that doesn't work, try putting
Set strTest = Test(Index)
as you're copying the textbox object ... not just its value