Is it difficult to chage VB6 source code for access Crystal Report 10 (from 8.5)?

Now I already have VB6 Program that use Crystal Report 8.5.
I have a plan to migrate Crystal Report to version 10 but I alway have some question about

Is it difficult to chage VB6 source code for access Crystal Report 10 ?
Or, Can I use the same code for access Crystal Report 10?
Or, How can I do? and What thing I must change for this case?

More Information:
I have already ask to Crystal Report Technical Support in my country. The answer is about we use OCX for access Crystal Report on 8.5 but we must use DLL for access on version 10.

When I went from 8.5 to 9.0 I had to rewrite a lot of code. I would imagine that going to 10.0 would be just as bad, if not worse.

It's sound terrible.
I don't know that Version 10 is make the same problem like Verison 9 or not. However, I think it OK is the code only change on restrict boundary. Could you advise me more information as a guide line?


If something like this may be OK for me....

xxxxxxxx
yyyyyyyy
xyxyxyxy
xyzyzyzx

[Change to]

11111111
22222222
12121212
12323231