spreadsheet manipulation of netcdf files

hi all,

I'm new to visad and indeed data visualisation in general.  I have found the 
visad.ss.SpreadSheet application extremely useful in RAD.

Q-A) Is it possible to use the SpreadSheet application to manipulate 
different variables in the same NetCDF file?
For example if I have a netCDF file with three dimensions:
1) Time
2) X coordinate
3) Y coordinate
And two main variables:
1) No of Males
2) No of Females
This is loaded into the spreadsheet cell A1.  I want A2 to equal the 
percentage of males
 (A1(No of Males) / (A1(No of Females)+A1(No of Males)))
this can then be animated over time to show population trends.

This is an example of course but I'm wondering if it can be done using the 
SpreadSheet as it is currently implemented.

Q-B) What file formats (apart from netcdf) support animation using the 
spreadsheet?
I am currently using netCDF as it is the only one I'm managed to successfully 
do animation with.

Thanks in advance

Hamish Carpenter