Regex API 2

What is the replacement code for using MidB and some other B functions when doing a Regex? Here is some super old splitbyregex code:

Dim out(-1) As String
Dim startPos As Integer

Dim re As New RegEx
re.SearchPattern = delimPattern
Dim rm As RegExMatch = re.Search(source)
while rm <> nil
  out.Add MidB(source, startPos + 1, rm.SubExpressionStartB(0) - startPos)
  startPos = re.SearchStartPosition
  rm = re.Search

if startPos < source.LenB then out.Add MidB(source, startPos + 1)

return out


And the SubExpressionStartB?

Have you checked the documentation???