how can I make this BOLD?

hello

I have this part of code

Me.txtOnPrep1.Text = c.Offset(0, 1) & Chr(10) & "B. No.: " & c.Offset(0, 2) _
     & Chr(10) & "from: " & c.Offset(0, 3) & Chr(10) & "to: " & c.Offset(0, 4)

How can I make the word "B. No.:" , :from:" & "to:" BOLD ?

thanks ...