How to use variables for configuration options for a node?

[codalf]

I am passing into a chat flow a variable with the version of a document set.
In a DocumentStore node, I then want to use a store which is based on the version, eg. version is 1 => DocSet_1, version is 2 => DocSet_2.
How is that possible?

If that is not possible, maybe another approach would be to use a VectorStore node and use a variable for setting the collection name. How can that be done?
I tried things like DocSet_{{$vars.version}} in the collection field, but the variable was not resolved.

Any ideas?