String Value from DropListbox

Hi there,
I have declared array elements as result of the choice made by the user within 13 DropListBoxes
        UserChoice(0)= ListOfColumns(dlg.DropListBox1) 'Ref
        UserChoice(1)= ListOfColumns(dlg.DropListBox2) 'Value
UserChoice(2)= ListOfColumns(dlg.DropListBox3) 'Dr
         ...  and so on.
 How can I make sure the string value from each of the DropListBox is correctly displayed in tasks  such as :
 - TableManagement and NewField creation - within field.Equation
   My formula in that equation is  = month(value from the DropListBox)  and i have it  as          
   Month(ListofColumns(dlg.DropListBox5) but it doesnt seem to be working.
- database.Gaps - within task.FieldToUse 
  I have currently ListOfColumns(dlg.DropListBox1) in the  function as per below (but it doesnt seem to    be working):
     Function GapDetection(MasterDb,UserChoice() As String)
'Set db = dbhome   
         Set task = MasterDb.Gaps
task.FieldToUse =  ListOfColumns(dlg.DropListBox1)  
MsgBox ListOfColumns(dlg.DropListBox1) 
task.UseCutoffs = False
task.Increment = 1
dbName =  "JE Ref Gap Detection.IMD"                   
task.OutputDBName = dbName
task.PerformTask
Set task = Nothing
Set MasterDb = Nothing
Client.OpenDatabase (dbName)
End Functiion