Setting an object using multiple variants

Hi,
I am new to VBA and I am sure that this is a very basic question but I would really like to know how to do this.
Sub test()
Dim q As Variant
Dim w As Variant
Dim txtbox As Object
q = "ActiveSheet.TextBox"
w = "1"
Set txtbox = q + w

txtbox.Value = "xyz"

End Sub

I know that there is an easy way to do this but I want to create a macro that fills all text boxes with a certain text. That aside, the purpose of this post is to find out why is it that when I set "txtbox" as object using "q" and "w", I still get an error telling me that my object is required. Please help.