Label name referring to subform

[NNothard]

Just a quick question, I can't seem to get this right (as usual )

I have a form and I want the label in the header to display the text from a field in a related subform. I have tried the following syntax to no avail:
=[Forms]![sfrmCompanyName]![LastName]

Any suggestions

Thanks in advance

Nicolas

 

[NNothard]

Thank-you very much, that worked first time.