accessing multiple instances

I need to query I2 using columns from I1. It may sound unusual etc.etc.

I have stored the field-values its just one column from I1 and want to connect to I2.
I thought that the following would work, but it didnt

declare
begin
execute immediate 'conn abc/abc_at_inst2 '; end;
/

Want to run something like this

declare
curosr c is
select 1,2,3,4 from inst1.table1 where ---- ; c_rec is c%rowtype;