[NTG-context] Howto metapost textext set or change basepoint (origin) baseline of text

Hi I have the following problem. I convert a eps file using pstoedit into meta post file. When running this file through mptopdf the resulting pdf image is as expected. When i include, using the input command, the file within a startMPcode endMPcode or startMPpage stopMPpage after replacing simple draw <string>... by draw textext(