Yes, indirectly through a function.
For example, if you had a global variable defined in a module that looked
something like this:
Public YourGlobalVariable As String
you might create a function in the same function that looks something like
this:
Public Function YourGlobalVariableValue() As String
YourGlobalVariableValue = YourGlobalVariable
End Function
You might then use this in a query like this:
SELECT
[Your Table].*
FROM
[Your Table]
WHERE
[Your Table].[Your Text Field] = YourGlobalVariableValue()