Method of ITextDocument
Calculate absolute distance between text positions
var pnAbsolute = TextDocument.AbsoluteDistance(pStart, pEnd, nLBStyle);
pnAbsolute = TextDocument.AbsoluteDistance pStart, pEnd, nLBStyle
long nAbsolute; HRESULT hr = TextDocument.AbsoluteDistance(pStart, pEnd, nLBStyle, &nAbsolute);