Forms :: Setting OnDblClick On A Subform

I have a form frmDisplayVars with a subform subfrmDisplayVars. The sub form initially has its RecordSource set to "" and is set dynamically from a maketable when needed.In the OnLoad for the main form, the subform RecordSource is set to a table "Table.Test". This is so that the load routine can execute a maketable query to create the form "Test" in advance. This produces a table from a crosstab query. All this works OK so far.

However, I wish to be able to double click on the datasheet in the subform to then open another form with data related to the cell/contol that was clicked on. Essentially creating a room occupancy table for a range of dates and rooms. Rows are rooms and columns are dates.

I have a problem with setting the OnBblClick for the subform controls.For example the 2 test code lines for the control "RoomName" illustrate.

Code:
Forms!frmDisplayVars!subfrmDisplayVars.Form!RoomName.Name
Forms!frmDisplayVars!subfrmDisplayVars.Form!RoomName.OnDblClick = "=TestMe()"

The first line works fine and returns as it should the name of the control "RoomName".It is the second line which I need to set the event code for OnDblClick which fails with error no. 2455 which suggests wrong syntax for referencing a control on a subform.I can't set the event procedures manually as they are not known in advance until the table "Test" is made so need to be able to set the control events dynamically.