Yes, in the general case. DNS supports this, bind zonefiles support this. If you're using a management UI, you'll need to check what's supported by that.
@ORIGIN example.com.
; ...
*.foo IN A 192.0.2.1
Note that if you create another record for an item in foo, then that will stop the wildcard from providing a record. Wildcards only match where no other name matches. So you'll need to explicitly provide the data that the wildcard would have provided.
@ORIGIN example.com.
; ...
*.foo IN A 192.0.2.1
fred.foo IN TXT "Fred was here"
fred.foo IN A 192.0.2.1
Yes, in the general case. DNS supports this, bind zonefiles support this. If you're using a management UI, you'll need to check what's supported by that.
Note that if you create another record for an item in foo, then that will stop the wildcard from providing a record. Wildcards only match where no other name matches. So you'll need to explicitly provide the data that the wildcard would have provided.