hello, i can't buy that dlc on my country. so  can anyone  trade me it for   something with the same price on steam?.  

What country is that?  Are you sure you can get it by trading?  That would make the block on the country kinda pointless.

https://support.steampowered.com/kb_article.php?ref=1266-QFZC-2141

 

It should be clear if the product you wanna purchase is region locked or unavailabe in your country. This is the kind of thing that are managed by Ubisoft and Steam directly and as a fan community, we won't be able to do much on our end.

I always use an official Oasis dlc when importing cdlc's so I don't think you have to use Cherub Rock even if the author used that song when creating the cdlc.

 

But, before you buy another dlc I would confirm with an expert.