OK, give this a shot; create another form (use Design View) and bind it to your table that has the age_band field. Add the field, age_band, to your new form by dragging the name of the field onto the design surface. Save your form and give it a name that indicates this form is temporary. I use a convention like A_A_age_groupQueryTest.
Fix the Select Case statement with the following code. Pay attention to the single quotes and double quotes and spaces, etc. You will need to adjust code for your names, add Case statements, etc.
Code:
'p_AgeBand will be the name of the control
'We will use the name to understand the literal text
'that needs to be used within the WHERE criteria
Select Case p_AgeBand
Case "ageBand66_70"
strWhere = strWhere & " OR age_band ='66-70'"
Case "ageBand71_75"
strWhere = strWhere & " OR age_band ='71-75'"
Case "ageBand76_100"
strWhere = strWhere & " OR age_band ='76-100'"
End Select
You will also need to add some code to your click event. Replace "Debug.Print strWhere" with ... where A_A_age_groupQueryTest is the name of your new temp form.
Code:
'Debug.Print strWhere
DoCmd.OpenForm "A_A_age_groupQueryTest", acNormal, , strWhere
This should open the temp form with Filtered results. I have to take care of a few things and will be away from my desk for a little while. If you have trouble, go ahead and upload your DB here. I will take a look at it. Just drag your temp form and the new form we have been working in to a new blank DB to upload. If you can, include the table. Just be sure to remove sensitive data. Compact and repair your new DB for uploading. Zip/Compress the file/DB before uploading.