This should be simple, just use the AddFontResource API...

Code:
Public Declare Function AddFontResource Lib "gdi32" Alias "AddFontResourceA" (ByVal lpFileName As String) As Long
Simply pass a font filename to lpFileName.
For example, to add Arial font, do this:

Code:
Dim lRet&
lRet& = AddFontResource("c:\windows\fonts\arial.ttf")

NOTE: I haven't tried this myself, but I don't see any reason why this should not work.