Hi,
If you are talking about the link between the LabVIEW UI and simulink parameters, than the tutorial below can help you out:
http://zone.ni.com/devzone/conceptd.nsf/webmain/955A9D79583A0AB686256DB8006672B8?opendocument#3
If you want to pass the value to another parameter you can just pass with normal LabVIEW tools. Doing it internally in simulink from LabVIEW that's not possible. If this is not what you mean, let me know..
Regards,
JV
AE