Tracking Excel?

Is there a way to track or display the steps that a spreadsheet is taking during calculation routines and vlookups?

I am supporting a user who complains that his Excel locks up on him whenever he is in a particular spreadsheet. This spreadsheet pulls data from various locations including Bloomberg.

After a while, Excel will being responding again but we would like to try and figure out where the bottleneck is occuring and fix it.

Anyone have experience with an issue similar to this?