For more advanced splitting of text, I'd personally use an inline function for the whole thing and actually split the input using String.Split()
If you'd rather use tokens, you can use an inline function solely to set a text variable to a tab character, which you can then use for the "textVariableOf" parameter of the "{TXTPOS:}" token.
E.G.
Inline C# Function: Set tab variable
Write [Blue] '{TXTSUBSTR:myVariable:0:{TXTPOS:tabChar:myVariable:}}' to log
Where "Set tab variable" contains
public class VAInline
{
public void main()
{
VA.SetText("tabChar", " ");
}
}