Windows Forms

Question

i need a textbox and button

in textbox i have to keep validation in windows form

 in text box 1st letter should start with 3

and 2nd letter should start with R||c

I MEAN R OR C

3rd and 4th should be OF||OH||OD

5TH LETTER SHOULD BE B or 0-9

and 6th to 12th it should be a numbers

only

total it should not exceed 12words in textbox