> SET LIBRARY TO mq_tools.dll
>
>In VFP6, we recompiled it, and it seems that the SET LIBRARY function won't work anymore for this purpose. Has there been a change, a restriction, in how FoxPro must talk to custom dlls?
>

You recompiled the .fll in VFP6? Do you mean that you recompiled the C source in VC++ #including the VFP6 version of pro_ext.h and linked with the VFP6 Winapims.lib library?

>When I use a DECLARE statement to declare up one of the functions in this dll, and then call the function, I get message "Cannot find entry point in the DLL". I made sure that the upper/lower case of the name is exactly the same both in the dll and in the DECLARE statement, but that was not the issue.

You can't just declare and call every function in a dll, only those functions that have been exported.

>
>We wonder if we just haven't compiled it correctly, and that is why the functions are not visible to FoxPro. I am not a C person at all, and our new manager who has worked with C is baffled also.
>

Read chapters 27 and 28 of the Visual FoxPro Developer's Guide (include in help.)

>Hoping to find a FoxPro guru who has dealt with this very problem.