Back in the old days I remember I had used Excel REPT function to hold a bar in a cell like the graph below (I can’t recall why I did this), but I am sure there is some great use of this trick out there. You can see the formula in the formula bar. You also need to set the font to Britannic Bold for this to work.
Good news is now you can use the same trick in Power BI as well . Chris Webb has recently blogged about this. Go check it out.