call-convention 74 is cc74

I have a subprogram that uses the functions
            call-convention 66 is dynamicWINAPI
            call-convention 74 is cc74

but to include it in .NET project has an error

            call cc74 'FindFirstFileA'
                by using reference findFileName
                      by reference WIN32-FIND-DATA
                returning fileSearchHandle

How to solve this problem?