[SOLVED] How to overlay a GameObject position at an NGUI Widget position

[bach]

I am pretty much looking for the opposite of NGUIMath.OverlayPosition

I want to position a GameObject viewed by World Camera
at the position of the NGUI Widget viewed by UI Camera

I've tried all sort of combinations without much luck:

1. Vector3 pos = nguiCamera.ViewportToWorldPoint(nguiWidget.transform.localPosition);
2. pos = Camera.main.WorldToViewportPoint(pos);

thanks

[cuidaguang]

Vector3 world_pos = Camera.main.WorldToScreenPoint (position);
pos.z= 0;
Vector3 ui_pos = UICamera.mainCamera.ScreenToWorldPoint(world_pos);
gameObject.transform.position = uipos;

[bach]

Vector3 world_pos = Camera.main.WorldToScreenPoint (position);
pos.z= 0;
Vector3 ui_pos = UICamera.mainCamera.ScreenToWorldPoint(world_pos);
gameObject.transform.position = uipos;

Thanks for pointing me in the right direction!

My code ended up as below:

1. Vector3 worldPos = UICamera.mainCamera.WorldToViewportPoint(nguiSprite.transform.position);
2. Vector3 uiPos = Camera.main.ViewportToWorldPoint(worldPos);
3. gameObject.transform.position = uiPos;
4.