Userform Textbox to input data to worksheet

I have some data that will be entered into a worksheet manually. I created a UserForm that asks for user input to find the proper workbook and then desired worksheet.This part works good. Here is where I need some help....
I have a textbox that a user will input numeric data (i.e. 1.012). What I would like to do is have the user type in the data and then hit 'enter' and place data in desired cell (C15) and then have the textbox retain focus so another value can be typed in and when 'entered' put in next cell (C16) and so on until I enter all 60 pieces of data.
I was able to get the data in the first cell (C15) but I have to click back in the textbox to regain focus and I can't seem to get the 'next' data to go to the next cell down.

Thanks in advance for any ideas/suggestions/solutions.

Robert