Hi Luis,
The Vision front panel should be located under C:\MeasurementStudio\cvi\toolslib\Vision\nimachinevision.fp
You just need to load this file as an instrument driver.
Since Vision 5, the function names have changed from IPI to IMAQ.  You will need to change your code to reflect that.  We do have an IPI compatibility library though, if you still want to make calls into the IPI library in Vision 5.
Hope this helps.
Ken Sun
Applications Engineering
National Instruments