Gift certificate code

I need to alter the Gift Certificate code generator to generate a code with only 5 digits with all cap letters (no small letters) Does anyone know how to revise this code below to make it do that?

'--- Start Generating Gift Code - This is just SAMPLE CODE
                Tn1=""
                For w=1 to CodeStrLen
                    Randomize
                    myC=Fix(3*Rnd)
                    Select Case myC
                        Case 0:
                        Randomize
                        Tn1=Tn1 & Chr(Fix(26*Rnd)+65)
                        Case 1:
                        Randomize
                        Tn1=Tn1 & Cstr(Fix(10*Rnd))
                        Case 2:
                        Randomize
                        Tn1=Tn1 & Chr(Fix(26*Rnd)+97)       
                    End Select
                Next
'--- Finish Generating GiftCode   

I'm not clear on whether you are wanting just alpha or if the alpha-numeric is OK, but to convert your lower case to upper case you should be able to simply add this after the For . . .Next loop:

Tn1=UCase(Tn1)