Custom column - convert datatype

I'm creating a question based on a table which has a column 'answers' - a TEXT field. This column can contain "this data", "15-Mar-24", "123.56" or anything really. I want to create a custom column which will convert this text to a number if appropriate (based on a filter on a different field). I see nothing in the expressions list which will do this. Can it be done? It seems like a simple ask, but I can't figure it out

unfortunately casting is not yet supported. I would suggest you make that custom column in a view