writing a custom get method for a scala map

I have a map which is something like

val m = Map("foo" -> "bar", "faz" -> "baz")

I need to write a custom get method, so that the key can be the key in the map with a number in the end.

So for example:

m.get("foo1") should return "bar"

I am looking for a good scala pattern to solve this problem.

Also I am generating the above map from a for loop using yield, so I can't do something like this

val m = CustomMap("foo" -> "bar")

Any solutions will be appreciated.

Thanks