how to pass Process ID to WinWait Function

[CanadianHusky]

Hello,

this line starts the app defined with cmd successfully and returns a valid (non zero) process id

AutoItX3Lib.AutoItX3 AIX = new AutoItX3Lib.AutoItX3();

int pid = AIX.Run(cmd, "", AIX.SW_MINIMIZE);

all the Window Managment Functions expect a string variable

this does not seem to work because the pid is an integer

AIX.WinWaitActive(pid);

How can I feed the WinWait function with the string parameter that it expects from the pid that was created earlier ?

The Form title of the app opened with cmd is variable and not known until it starts. 
With Standard AutoIT and SciTE I was able to feed Window Handles and Process IDs into Window Functions without a problem
I read Window Titles and Text (Advanced) in the main help file and many options how a Window title can be passed in are explained, all for the scripting environment.
even the WinGetHandle function on the C# binding expects and returns a parameter of type string, not a Pointer or (int) Process ID

thanks in advance for any tip

[Zmy]

AutoItX3Lib.AutoItX3 AIX = new AutoItX3Lib.AutoItX3();
int pid = AIX.Run("mspaint", "", AIX.SW_MAXIMIZE);
string spid = pid.ToString();
AIX.WinActivate(spid, "");