2 domain transfer

Hi… i want to explain my problem (or future problem)

i have 2 domains domain1.com and domain2.com, now the 2 domains point to 1 hosting (hosting.com)

now i want to transfer domain1.com to dreamhost (domain1.dreamhosters.com/forum)

now i have a subdomain for test and configure the new forum, when i finish it, i like to transfer the domain1 to domain1.dreamhosters.com/forum

so when users go to domain2.com they get the old site and when users go to domain1.com the new one.

in few months i want to transfer all my domains to the new dreamhost hosting

is posible? to do all this?

Sorry for my english =P