[Dx4win] Invalidate QSO

[F6EXV Paul]

  Hello all
Before I try this, I would like to know if anyone else has done it 
successfully.
I need to invalidate various QSO in DX4Win (version 8.03) and have read 
that putting a "!" before the callsign in the callsign box will work. 
Like !XZ5A for example.
Anyone has tried ?

This is in order to upload my log to Clublog without the callsigns which 
I know are invamlid for DXCC (but that I want to keep in my log).

Thanks
73
Paul F6EXV