Max length of FileName property of Common Dialog Control

I am using common dialog control in my Project. I am working on VB 6.0.
In my project I want to select multiple files in Common dialog control.
So I am using 2 flags like this:-
CommonDialog1.Flags = cdlOFNAllowMultiselect Or cdlOFNExplorer

I am splitting the fileName returned from the control like this to get indivisual file names.
fileNameArray = Split(CommonDialog1.fileName, vbNullChar)

Now the problem is if I select some no. of files say 12, then if the filenames are too long then the filename is returned as NULL. ie. no file is selected. But if filenames are short it lets me select even 20-25 files at a time.
So my question is what is the maximum no. of characters allowed in the filename property of common dialog control?
Can anybody help me?

CommonDialog1.MaxFileSize = 10000

max = 32K, default = 256