@patrachar8 I believe the number you're porting in needs to be active. As well, if it's been inactive for 6 months or more, there is a chance that the number may have been re-assigned.
Do you mean from PM to PM?
It cannot be done. Number has to ported elsewhere first, then back in. Bell is a low cost option.
To go on another interpretation...if your "old number" service can do call forwarding then of course you can forward it to here.
But pizzaeh has probably interpreted your question correctly.