Hidding a field in a specific MA

Hi experts,

I'm trying to hide a field: ZFIELD, in a specific Master Agreement: 00001XPTO.... but its not working. Is it really possible this case?

Using page customization:

Field Name: ZFIELD

Property: Hidden

Value: Yes

Dimension on Parent: NO

Dimension Field: UNIQUE_DOC_NAME

Dimension Field Type: Object Reference

Class Name : Master Agreement

Dimension Value: 00001XPTO

After creating this page customization, ZFIELD is hidden for all Master Agreements, but I need to hide it only for MA 00001XPTO.

Thanks,

Adilson