subquery in front clause between two dbs

[leandro roggerone]

Hi guys , I need to cross two databases with a from clause:
So far Im using two differents queries , like:
From db1

select * from fsan_top_100 order by hits desc limit 5;
+--------------+------+
| fsan         | hits |
+--------------+------+
| ZNTS035D41E3 |  172 |
| ZNTS0344E3BE |  164 |
| ZNTS037FB6ED |  156 |
| ZNTS037CD31C |  150 |
| ZNTS035D3D81 |  150 |
+--------------+------+

Then ; from db2 I need to do:

select ip_address from ZNTS035D41E3  order by date limit 1;
select ip_address from ZNTS0344E3BE  order by date limit 1;
select ip_address from ZNTS037FB6ED  order by date limit 1;
select ip_address from ZNTS037CD31C  order by date limit 1;
select ip_address from ZNTS035D3D81  order by date limit 1;

So ... is it possible to join both queryes , so far I have:

select ftth_cpe_history.ip_address from (select fsan from ftth_cpe_snap.fsan_top_100 order by hits desc limit 5)  ffsan ;

It returns :

ERROR 1054 (42S22): Unknown column 'ftth_cpe_history.ip_address' in 'field list'

I dont know how to continue ...
Any idea would be wellcome,
Thanks.