I've managed to kludge together a workaround for now but I expect there's a more elegant way. I pick whipped the position attribute of the Numbers effect to the position of the parent text line. That made the numbers jump to the anchor point and then I manually added an offset in the expression to shift it over to the gap in the text line where I wanted it to appear.
Still interested in better solutions if there are any. Many thanks in advance!
Parenting. EZ as pie. This locks one layer to another.
That was the first thing I tried, but when I parented the effects layer to the main text layer it didn't work. The Effect has an absolute position attribute that appears to override the position attribute of the layer itself, so it won't move with the parent.
Simply write it in an source text expression. Create a slider whose value you animate, then include it in the text:
myNum=myVal.toFixed(0) //define number of decimal positions, zero is none
"We are "+myNum+" strong!"
That works great, thanks!
Pre-compose then parent or use Mylenium's solution