If the AutoCAD text element was created using the older TEXT command, which does not support multiple font styles, then you should use a font-style conversion dictionary file. The conversion file will have no effect on MTEXT (multi-line text) elements.
During Open, a text having a font that is listed in the dictionary will be converted according to the dictionary specification. The slant parameter is handled the same way as during Save (see below).
You can pick the requested font name from the pop-up list. Its name will appear in the ARCHICAD font field. In the AutoCAD style field, type the name of the style you would like this ARCHICAD font to be converted to in the resulting DXF/DWG drawing. Or vice-versa: after opening DXF/DWG files, text elements using the style in AutoCAD will be displayed in ARCHICAD using the font specified in the ARCHICAD font field. In the Oblique angle field you can specify the angle of the font in ARCHICAD.
During Save, texts having the font specified on the ARCHICAD side of a dictionary item will be exported in the font specified on the AutoCAD side. If the slant parameter is 15 (15 degrees) or greater, the exported text will be in italics. Usually, an italic style has an oblique angle of 75 degrees. Unless a template file is selected, the style will use the AutoCAD counterpart of the ARCHICAD font. (A font conversion file specifies the best match, regardless of the platform ARCHICAD is running on).