Ok people. Maybe this is a little bit too late for this game, but I wanted to play with my girl and desided to unlock spiette character for her.
And I managed to do it.
However...I had to replace Hardcore spy suit in order to activate one of the female skins.
Here are instructions:

1) go to ..\SCDA-Online\Packages\_Common\Video
And delete Hardcore_Spy.bik file
Make a copy of Hardcore_Spyiette.bik and rename that copy to Hardcore_Spy.bik

2) Now you need a HEX editor. I personally used HEX editor Neo.
Go to ..\SCDA-Online\System\PC
And open SC4Specific.u with your HEX Editor search for a line "PawnSpy_Zero" we will start from here. Below you will see line

.PawnSpy_One.... .APipeHPrToSt....
using REPLACE method change PawnSpy_One to PawnSpiette_One
It will look something like this .PawnSpiette_One .APipeHPrToSt....
The number of digits MUST be the same...DO NOT add or delete anything..only replace in order to maintain the same size of the file.

Scroll a bit lower and find
.PawnSpiette_One.... .PawnSpiette_Two....
Change PawnSpiette_One to PawnSpy_One
You will get something like this
.PawnSpy_One_One.... .PawnSpiette_Two....

Now we need to get rid of that extra "_One" we cant just delete it since file size will change
So we just change bit codes of "_One" from "5f 4f 6e 65" to "00 10 00 07"

Save and go check your unlocked skin. Dind't test it for MP, most likely it won't work or kick you for hacks... however..if both players have this mod...it should work.

And yeah...do not forget to backup your files before you start screwing with them.

Cheers.