Is there an object like [select] which outputs numbers?
i.e. send an output number to the corresponding outlet if the input matches the creation argument, if not: output nothing (nothing as in the lack of output, not zero).

this may be a stupid question but I haven't been able to find an object that does this.
any help would be greatly appreciated.

You could easily build this by using [select] for your creation arguments using the bangs from [select] to trigger message boxes.

[select 1 2 3]
| | |
[1( [2( [3(