you can achive absolute positioning in VS very easy.
Create a new page. With the cursor on your div (is autmatically created) choose Format/Position... and the Absoulte.
Next (in design mode) drag the size of the div to give you enough space.
Place a control in the div (drag from Toolbox) and again choose "Position Absolute" - drag the control to what ever place you want.
The following code shows the result:
| <div style="z-index: 1; left: 10px; top: 15px; position: absolute; height: 286px; width: 1873px">
| <asp:TextBox ID="TextBox1" runat="server" ontextchanged="TextBox1_TextChanged" style="z-index: 1; left: 407px; top: 169px; position: absolute"></asp:TextBox>
You can copy it to a new page an see who it works.
In VS - options there is a setting (I can just guess the names since my VS is german) at:
Extras (tools I think)
HTML Designer (left in the tree)
CSS Styles (the fourth entry)
For controls ... via Toolbox or paste or drag and drop.... use absolute positioning.
Set this checkbox - so absolute positionin will be default.