AutoCAD Inventor :: Change Style Of Existing Dimension

I'm chasing the syntax on what i hope is a very simple procedure.

We have a project for re-design and manufacture here (Australia) of a machine that has been designed and detailed in one of our US offices. For this reason, we will be wanting all dimensions in mm etc, rather than inch.

My intention is to open the idw(s), update the styles library (done, i think...), change the active standard to "AS Metric" (got the code sorted for that too), and then change all dimensions to AS Metric.

So far i have each of these 3 processes in a different sub, called from a master. But my problem is in changing the style. I could change a dimension's style to match that of another existing style:

Set oGeneralDimensions = oSheet.DrawingDimensions.GeneralDimensions.Item(1)

but I am having trouble setting is to the active style.

My module:

Sub ChangeStyle()
Dim oIDWDoc As DrawingDocument
Set oIDWDoc = ThisApplication.ActiveDocument
Dim oSheet As Sheet
Dim oDim As DrawingDimension
Dim oDimStyle As DrawingStandardStyle
Dim oGeneralDimensions As GeneralDimension

[Code]....