In our viflow help in the program you will find a detailed explanation in the article "Customising the Graphic Template" how to proceed and fix your own logo in the upper right corner of your graphic template.
For this we use the ShapeSheet programming of Visio.
Our help will give you the formulas for the upper right corner of your hand. For other positions you will find the alternative ShapeSheet formulas here:
If you want to place the logo at the bottom right:
If you want to place the logo at the bottom left:
You can adjust the respective millimetre values as required.