ok,
click Start/Control Panel/Folder Options
this will bring up a new menu along the top of that box you will see three tabs
General | View | File Types
click View
in the box that is titled [ Advanced Settings ] there is a list of settings!
Now, about halfway down there is a yellow folder icon and two selection buttuns under it.
select the [ O Show Hidden Files and Folders ]
hit ok then close the window.
now you should be able to navigate to the mods folder wich should be something like this...
C:\Documents and Settings\hp_owner\Local Settings\Application Data\Ironclad Games\Sins of a Solar Empire\Mods
...in my string it happens to be what I named myself when I installed XP which is "hp_owner" yours of course will be different.
good luck!

ds