OK I think I figured it out.

I declared "msgString1" as a public variable and set it to this in my code:
msgString1 = "Some text here..." & vbNewLine _
& vbNewLine & "And some more text here " & myVar1 & " more stuff."

Then I added a label named "msgVar1" on the userform and set it like so.
Form1.msgVar1 = msgString1
Form1.Show

It seems to work but I was hoping someone could confirm this is an
acceptable way of doing it.

Thanks - PJ