Question: Is どうやって considered to be a single word all to its own (acting as an interrogative adverb?)? Or is it just どう＋やる ("doing + how"), and no different than any te-form construction?

In the following, it seems to be acting as a single word:

駅までどうやって行きますか。

How can I get to the station?

...since if どうやって were just a て-form construction, then 駅まで would have to be contiguously paired with 行きますか, I think? As in:

(どうやって)(駅まで行きますか)。

as opposed to the way it is now:

(駅まで)(どうやって)(行きますか)。

So the fact that どうやって breaks into 駅まで行きますか makes me think that it is genuinely a single word, and not just どう + the て-form of やる.

Is this correct?

Question: Is どうやって considered to be a single word all to its own (acting as an interrogative adverb?)? Or is it just どう＋やる ("doing + how"), and no different than any other te-form construction?

In the following, it seems to be acting as a single word:

駅までどうやって行きますか。

How can I get to the station?

...since if どうやって were just a て-form construction, then 駅まで would have to be contiguously paired with 行きますか, I think? As in:

(どうやって)(駅まで行きますか)。

as opposed to the way it is now:

(駅まで)(どうやって)(行きますか)。

So the fact that どうやって breaks into 駅まで行きますか makes me think that it is genuinely a single word, and not just どう + the て-form of やる.

Is this correct?