in both vb6 or VB.Net, you can split the string into elements, and take the first element, or you can use the built in string functions.

'VB.Net: both return "ABC"

Dim SomeString As String = "ABC DEF GHI"

Dim val = SomeString.Substring(0, SomeString.IndexOf(" "))

Dim arr() As String = "ABC DEF GHI".Split(" ")

val = arr(0)

'VB6

Dim SomeString As String

SomeString = "ABC DEF GHI"

Dim val As String

val = Left(SomeString, InStr(SomeString, " ") - 1) '-1 to remove the space

Dim arr() As String

arr = Split("ABC DEF GHI", " ")

val = arr(0)