Illustrator SDK :: Getting Global Position Matrix For Each Text Character

I need to get the position and orientation of the first and the last character in a text frame art, that is, I need its  matrix.There are a number of functions in the API that is supposed; here's a snippet from the file ATESuites.h
 
Return transformation matrix of this run.The matrix returned spesify the full transformation of the given run.  You need to transform the origin by IGlyphRun::GetOrigins() and

concat with ITextFrame::GetMatrix() in order to get the location of the glyphs.
ATEErr (*GetMatrix) ( GlyphRunRef glyphrun, ASRealMatrix* ret);
 
Hence, getting the matrix of the first character or glyph should look something like this:
 
AIErr
VMGetFirstTextMatrix(  AIArtHandle textArt, AIRealMatrix *matrix)
{
    ASRealMatrix frameMatrix, glyphMatrix;
    ASRealPoint firstPoint;
    try
    {
[code]....
       
But the coordinates, either returned in frameMatrix (tx and ty) or the firstPoint are obviously wrong. It appears that they an offset which is allmost constant.  The x-values are approx 7664 points too large (give and take a few decimals), and the y-values are approx 7893 too large (also give and take a few decimals).