Converting Large String To HEX More Quick Any Help Please

[Romania]

Hello frndz how are u ?
i want to convert large string to HEX and that takes a lot of time (3-5 minutes) using the normal StringToHex Function posted some where here ..

Public Function StringToHex(ByVal StrToHex As String) As String
Dim strTemp   As String
Dim strReturn As String
Dim i         As Long
    For i = 1 To Len(StrToHex)
        strTemp = Hex$(Asc(Mid$(StrToHex, i, 1)))
        If Len(strTemp) = 1 Then strTemp = "0" & strTemp
        strReturn = strReturn & Space$(1) & strTemp
    Next i
    StringToHex = strReturn
End Function

i want you please to help me make it more quick ..
btw i knew that there is 2 ways to do that using api's or without ..