There is no "automatic" way of doing this since the controls are different objects. Did you luck out and find that the controls are typedefs? Then, you could just change the typedef. The only other way of doing it is with the "not officially supported by NI" method of scripting. You can head over to the LAVA forums to delve into this, but be warned that you can seriously mess things up with this. Also, you can't create code to use scripting in LV 8 since that requires a license. Instead, you have to create it in 7 and then try to see if it works in 8.
