VB如何调用.M文件编译成的dll文件

[lancelotdevil]

Declare Function jiafa_v Lib "jiafa.dll" Alias "_jiafa_v@20" (ByVal emsg As String, ByVal nlhs As Long, ByRef plhs As Long, ByVal nrhs As Long, ByRef prhs As Long) As Long
这段声明是什么意思，后面的5个参数代表什么，调用是时用jiafa()还是jiafa_v()?