Finish/end dates

Hi Guys,
Hope you are all well.

I am currently working on a project where there is an end date of mid 2009.

However there is also a much more important "go live" date which is much sooner of mid october 2008 from when the majority of tasks will be completed.

When the plan was initially created by someone, he based the plan from start date. As a result, when I want to look at the critical path, the system is only picking up tasks near the end date of mid 2009.

As a result, in my opinion the critical path doesn't give me an accurate reflection of the current situation.

Is my interpretation incorrect or is there another view which will let me determine tasks on the critical path? Or can I change the finish date and bring it in nearer to this mid-way point in the project?

thanks very much
Linda