Pension field missing from the screen

We have requirement to store employee pension reference number. I looked at infotype 0071 (Pension Funds GB) and found the field Employee reference number (PA0071-EEREF). I thought it would be the perfect place to store this number.

However when I went to create this infotype in transaction PA30. This field does not show up. I looked the IMG in u2018Change Screen Modificationsu2019 and this field is not shown in any of the screens associated with module pool MP007100. I tried to create an alternatice screen but once again this field does not show up.

How do I add this employee reference field to the screen so I can update it?

Thanks in advance

Shamshudin