Where is the TEXTFORMAT Property?

In access 2007 I can set a table field to be a memo and further set it to 
contain rich text by setting the filed's TextFormat property. My question 
is... how do I do this in code? I can't seem to find that property, or am
I 
going about it wrong?

Here is how I thought it would work:

  tblTableDef.Fields.Append tblTableDef.CreateField("SpecialOfTheDay",
dbMemo)
  tblTableDef.Fields("SpecialOfTheDay").TextFormat = acRichText

or something like that.

Thanks!
Paul