Slice or dispaly Last,First,Middle name where each column has a char limit

Good morning Adobe community,

Our current forms mapping is setup to display a member's name by the following order. Last,First,Middle in a single field (ie Johnson,Gary S). Where Last,First,Middle have their own column with character limit in our table dictionary. There is only a space between first name and middle.

Char Limits for each column:

Last 80

First 20

Middle 20

I'm trying to break the names apart (similar to slice) and re-display the name in a single field such as: Gary S Johnson. Were each name char limit varies. Is this possible? I appreciate any assistance as this is beyond me.

Phil