You sent bitcoins to an address in a wallet you haven't set up yet? That sounds impossible. Where did you get the address? All you need is the private key. You can import that into any wallet.
Where do I get the private key?
Every address has a priv key, which is needed to control the funds in that address, don't know how msigna works but you must be having a key for the address you sent those coins to. How much did you sent?