Use this.
Final=Substr([Dim1];1;Pos([Dim1];";"))+Substr(Substr([Dim1];Pos([Dim1];";")+1;Length([Dim1]));1;Pos([Dim1];";")-1)
First Part=Substr([Dim1];1;Pos([Dim1];";"))+Substr(Substr([Dim1];Pos([Dim1];";")+1;Length([Dim1]));1;Pos([Dim1];";")-1)
With this i am extracting the part upto first semi colon.
Second Part Part=Substr([Dim1];1;Pos([Dim1];";"))+Substr(Substr([Dim1];Pos([Dim1];";")+1;Length([Dim1]));1;Pos([Dim1];";")-1)
With this i am extracting the part after first semicolon to next semi colon.