>I try to use an .OCX developed in Visual Basic 6.0 but i have a lot of errors. How can i do this ?.

Supposed you don't run them in VFP7, just do that ! it will help definitly.
To my findings an external OCX should just work fine, especially if it was written in VB. However, the OCX itself obviously must comply to the standards for OCX. And if it doesn't ...