Variable in Picklist Criteria

Variable in Picklist Criteria

Hello, I need help.
I have a form X with fields OPIDX and Name.
In another form Y, I want the user to input a value (OPIDY) which will seek to form X in a field / column specific (OPID given by the value provided by the user in the form Y), to then mount a dropdown.

Example:
Lookup_1
    (
        displayname  =  "Lookup 1"
        type  =  picklist
        values  = FormX [input.OPIDY].name
        width  =  206px
    )

where,
"OPIDY" would be a variable input by the user.
However, it is not accepted.


How can I do this?