How To Pass Table Fields Names From VBA To Query

I've been developing an Access database to keep track of my company's ongoing projects. There's also a form to browse the history of users actions within the program. It's based on table tbHistory that stores actions and parameters as numbers (for example eventId = 1 is "logged in" and eventId = 2 is "logged out"). I've been using a query to translate those numbers to text with a syntax like:

Code:
IIf([tbEvents].[EventId]=1 Or [tbEvents].[EventId]=2;[tbEvents].[EventDesc];IIf([tbEvents].[EventId]=5 Or [tbEvents].[EventId]=6;...

It worked fine but eventually the expression within expression builder has grown to the level that exceeded allowed limit and I couldn't develop my statement any more.. I decided to develop a vba function that would take eventId as a parameter and would retrieve a string, here it is:

Code:
Public Function translateHistory(eventId As Long) As String
Select Case eventId
Case 1 To 2
translateHistory = ""[tbEvents].[EventDesc]""
Case 6
translateHistory = "[tbEvents].[EventDesc] & "" <b>"" & [tbFormDesc].[FormName] & ""</b>"""

[Code] ....

And in my query I replaced that extremely long expression with just translateHistory([tbHistory].[eventId]). It seems to work, but the result it brings is a pure string with table names and fields - in other words, the query doesn't recognize it should be replaced with appropriate value. Here's the output I get:

Of course I'd like "[tbEvents].[EventDesc]" to be replaced with appropriate value of field "EventDesc" from table "tbEvents" as it used to be.