I have this piece of code for adding a link to an index.html in a directory based on a timestamp. `$(tstampm)` is a function that generates a timestamp.

```
export tstampm=$(tstampm)
echo 'output from sysuser database - <a href="sysuser/model01-$tstampm"</a> <br />'  >> /home/sysuser/docs/dbmodels/index.html

```

The quotes in the href prevent expansion of the bash variable. What is the correct syntax for getting it expanded?

Note that the double quotes for the `href` are enclosed in single quotes for the `echo` command itself.