Hi Raphael,
IAR projects are not compatible with CCS.
If you have the source code you need to create a CCS project with it/ convert your project to CCS. The compiler directives are different etc so some changes are very likely necessary.
Note, a quick look at the example. ... If this is an 8051 based radio product, it is not at all supported in CCS.
I hope this clarification helps.
Best Regards,
Lisa