Different sub domains to different servers

I have 2 sud-domains & 1 domain, viz test.example.com, dev.example.com and example.com I would like to point each of them to different shared servers. Can someone advise if this is possible and how?

test.example.com -------> ipage account 1
dev.example.com -------> hostigator/ ipage account 3
example.com       --------> ipage account 2

I would like to have all my applications within same domain structure but under different servers, so if one is down, the other is not impacted.
The shared server links are - ipage & hostgator