Try to divided in two separate greps.
Find what: (\d)([\l\u])
Find what: ([\l\u])(\d)
Change to: $1~%$2
The original query posted would match EITHER a digit and uppercase pair OR a digit and | (pipes or bar symbol) pair and Salah's expressions will match a digit and any upper or lowercase
If the object is to match only a digit and uppercase pair and separate them with a sixth space, I would use: (\d)(\u) and (\u)(\d) for the find expressions and $1~%$2 for the change
Is it possible or any other query that I could search both the things at the same time & replace it them.
If you have any other solution please give.
Try thius on a copy of the file becasue it may have unintended consequences:
Great job & thank you!