I make sales drawings for a manufacturer. In these drawings I show both metric and imperial measurements. Example: 27' 8" 8433 mm. What I normally do is use a conversion calculator someone made in Excel. i type the distance in Excel, then type the answer in CoreI onto the sales drawing. I would prefer it if Corel Draw could just do it. So if it type the metric distance, Corel will automatically insert the correct feet & inches. Along with imputing the feet and inches, Corel puts in the converted metric distance. I tried this with importing a table from Excel into Corel. It did sometimes work, but would Crash Corel constantly. I use Corel Draw Graphics suite X7.
They are dimensions on drawings. Sometime the dimensions are in a line of text, or displayed using the Corel Table tool. Imperial in one column, metric on the other. The line of text I know will just need to be typed out, and using excel to get the conversion. The dimensions are NOT to scale.
You could use the dimension tool and set one of the dimensions to inches or mm depending on what you have set as default. If you want to be tricky you could make a macro as Myron sugested.