Access VBA: OpenForm To A Specific Record

I am not a specialist, but am trying to create an application with Access 2000to manage our company’s orders. I have a table called ‘Service’ containing descriptive data on the type of service requested. This table is linked to several other tables, with ‘ServiceNo’ as the primary key linking most of them. The service number is not an autonumber, but a counter incremented through code, for specific reasons that I won’t develop here.

I have created two forms: one to consult all the service records (F_Service_Consult), with a button to open another form that allows the user to add a new service record (F_Service_Add).

When the new service form opens, the service number counter is incremented and this number is assigned as the new 'ServiceNo' in a new record added to the ‘Service’ table (using the SQL ‘Insert’ command). I would like this form (F_Service_Add) to open on this record only. In the code that creates ‘ServiceNo’, the correct value is contained in a variable called ‘lngServiceCount’. I have tried using this code to open my form:

Dim stDocName As String
Dim stLinkCriteria As String
stDocName = "F_Service_Add"
stLinkCriteria = "Forms![F_Service_Add]![ServiceNo]='" & lngServiceCount & "'"
DoCmd.OpenForm stDocName, , , stLinkCriteria

When I run the code step-by-step, the correct value is shown for ‘lngServiceCount’ when the mouse hovers over the variable (for ex. ‘155’). When the form opens, I have 1 record (Filtered), but nothing shows in the ‘ServiceNo’ text box.

I have deactivated the code that is in the ‘OnCurrent’ event procedure of this form to avoid any interference.

There are many sub-forms on the main form, which also contain the ‘ServiceNo’ in text boxes.

When I use this command to open the form:

DoCmd.GoToRecord , , acLast

the form opens correctly, with the correct ‘ServiceNo’, but ALL the records are opened.

The variable type for ‘lngServiceCount’ is a long integer. (I hope that is the correct term in English, because I am using a French version of Access).

I would be very grateful if anyone could tell me what I’m doing wrong. I’ve tried to be clear, but if more information is required, I would of course provide what’s missing.
Thanks in advance.