Found this on the web ... kind of kludgey ... put it works:
Start WordPad the Way You Want
Every time I start my WordPad program, it uses the default font setting of
point size 10 and I have to change it manually to the size I prefer. How can
I change the default font size, style, and other properties?
Sam Cimino, Merrillville, Indiana
The short answer is, you can't. But you can work around this limitation
fairly easily. Start WordPad, and if you have any boilerplate information,
such as a logo or a letterhead graphic, type or paste that into a new
document. Move the cursor to where you want to start typing your text, and
type a space. Select the space you just typed, and apply the desired
typeface, size, alignment, and other settings (see Figure 3).
Now choose File, Save As, select a location that is unlikely to be moved or
deleted, and give the file a name such as Template. Click Save. Now choose
File, Save As again, but this time right-click the file you just saved in
the dialog box, and select Properties. Check the Read-only box and click OK.
This will protect the file from accidental changes. Click Cancel in the Save
As dialog box.
Right-click the Start button and choose Open. Navigate to the shortcut that
you use to launch WordPad, right-click it, and choose Properties. Select the
Shortcut tab, click the Target box, and press End to make sure the cursor is
at the end of the command line. Type a space, followed by the path to your
template file. If the path contains any spaces or long file names, enclose
the entire path in quotation marks. If the program (Wordpad.exe) is already
enclosed in quotation marks, you'll end up with two sets of quotation marks.
For example, your final Target command line might read "C:\Program
Files\Accessories\wordpad.exe" "C:\My Documents\Template.doc" (your path may
differ). Then click OK.
The next time you launch WordPad, it should open your template with the font
you prefer. Because you made the file read-only, you won't have to worry
about overwriting the template. If you choose File, Save instead of File,
Save As, WordPad will still open the Save As dialog box, prompting you to
save the file with a new file name each time you start a new document. You
can extend this tip to create multiple WordPad shortcuts, each opening a
template for a different purpose.