You need to modify the button (or create a new one). The current looks like this:
Print FOLDER
To enter the name change it to this:
@nofilenamequoting
Print FOLDER TO="D:\Vic3D\Past\Meeting Show Lists\{sourcepath|nopath|noterm}.txt"
Button as XML
<?xml version="1.0"?>
<button backcol="none" display="both" label_pos="right" textcol="none">
<label>Print Folder</label>
<icon1>#printfolder</icon1>
<function type="normal">
<instruction>@nofilenamequoting </instruction>
<instruction>Print FOLDER TO="D:\Vic3D\Past\Meeting Show Lists\{sourcepath|nopath|noterm}.txt"</instruction>
</function>
</button>
You might like further automation, have a look here:
https://www.gpsoft.com.au/help/opus12/index.html#!Documents/Print.htm
How to do all this: