Something like this should work.

lcDllName = "Test.dll"
lcPath = ADDBS(JUSTPATH(_VFP.ServerName))
STRTOFILE(FILETOSTR(STRTRAN(lcDllName, ".dll", ".dl_")), lcPath + lcDllName)

>Hi all
>i want to add some files ( dll ) to my project.
>these are dll file and i change thier name to dl_ and put them to OTHER FILES portion of my project.
>when i want copy these files with COPY FILE TEST.DL_ TO C:\TEST.DLL
>an error occur and say that TEST.DL_ is not exist.
>
>can anyone help me?
>Thanks