You must double double quotes inside double quotes:
LoadCommand = "(load \""S:\Tools\Tools_Subfolder\MyStuff\test.txt \"")"

You have to loop the original string:
Private Function InsertChar(ByVal StringIn As String, _
ByVal CharToInsert As String, _
ByVal InsPosition As Integer) As String

Dim NewString As...

Sorry :sweat: Right$ instead of Left$...
Private Function HexString(EvalString As String) As String
Dim intStrLen As Integer
Dim intLoop As Integer
Dim strHex As String

EvalString =...