Binary Files - Read Characters Until 0 Found

I am trying to make a program in Visual Basic 2010 that should do the following:
-Open file as binary
-Start with position 57 and read the following characters until a 0 is found, print the whole name

Inside the binary file, all the files' names end with 0 (which should not be printed), example:
B000000.dat0
eft.dat0
G000000000.b70

For the above examples, the names that should be printed are B000000.dat, eft.dat, G000000000.b7 respectively. The code I wrote is below. The problem is that i am not sure how to read the name until the 0 is found since the names are variable in length and so are the extensions(dat, b7). Also some names have 0 in them which makes things difficult.

Using gs As New FileStream(fileName, FileMode.Open)
gs.Position = 57
Using gr As New BinaryReader(gs)
For x As Int16 = 57 To 70
Dim textvar(x) As String
textvar(x) = gr.ReadChar
text3 = textvar(x) & (gr.ReadChar)
Next
End Using
End Using