Need help with MS-Access Query

Experts:

I need some help with designing a query.  

The attached (testing) database contains the following:
- Table1
- Query1
- frmLogin
- rptGeneric

Process upon opening the database:
1. Open form "frmLogin"
2. Select any value from the listbox (this will open 'rptGeneric')
3. Then, open query 'Query1'

Additional Information:
- Query1 displays the average value for the 3 fields (Table 1)
- The 4th field "FormListBoxValue" is an expression which displays the last selected value from "frmLogin"

Here's what I need help with:
- Use the expression value (e.g., "AVG_3_Digit") as a baseline for another SQL expression so that I can compute the AVG value of any of the 3 fields based on whatever was selected.

For example (pseudo code) for the 2nd expression.  For example, change SQL from/to:
From: "SELECT Avg(Table1.[2-DigitNumber]) AS AVG_2_Digit FROM Table1;"
To: "SELECT Avg(Table1.[Forms]![frmLogin]![ListBoxTest]) AS AVG_2_Digit FROM Table1;"


Question #1: The proposed (pseudo) code -- with the [Forms statement] -- does NOT work.  How can I utilize a selected value from a form as field input for a SQL query?

Question #2: Right now, the form's listbox values mimic the query expressions (e.g., "AVG_2_Digit").  In the actual database, I need to be more descriptive with options in the form's listbox.   For example, the listbox may include options such as "Run report with average of 2-digit numbers."  That said, how can I translate that listbox value to match up with the actual field name [2-DigitNumber] or [AVG_2_Digit]?

Well, first things first... if I can get help with question #1, that would be a great starting point.

Thank you,
EEH
TestingDatabase.zip