Freezing cells during filter operations

[lparno]

I posted a problem yesterday, which I have worked around, now I am looking to tidy it up a little bit.

Is there anyway to freeze a cell/s (merged) so that it stays visible and the same size when you apply a filter?

Basically I have some title blocks, and when I filter the data some of them shrink due to cells being hidden. I have attached the workbook with the personal data removed. The cells I would like to freeze are the first column (equipment, personnel etc) and the 3 title rows (project 1, 2, 3).

In order to keep them visible when running the filters I have kept 'blank' shown, but it makes the sheet look messy. Ideally, for example, when filtering to only show high priority tasks, I would like the blank cells to also be hidden, but still have the 3 groups visible and the titles left the same size.