I think you are asking about editing an Excel file.
Can you use macros?
Are you using symbols?
Are you editing an image imported into Excel?
Can you share an example of your file?

Here's a copy of the excel file i made.

So i was asking my self if there's another way more efficent to make it? And byt the way is it correct ?
The thickness of the plates for the tanks are like this :

- Demineralized Water Tank : between 24 and 8 mm
- Desalinated Water Tank : between 11 and 6 mm
- Fire Water Tank : between 15 and 6 mm
- Fuel oil Tank : between 20 and 8 mm
- Potable Water Tank : 6 mm
- Service Water Tank : 6 mm

• https://files.engineering.com/getfile.aspx?folder=3d7618f8-2abd-46cf-9b2a-4

I just draw it in AutoCAD. Not that hard to work out manually.

It is not the shell that is hard to draw but it's rather the radiography spots that are boring and repetitive especially when naming them one by one.

This could be simply done with AUTOCAD and you may follow the clause API 650 , 8.1.2 but i do not understand the reason for water tanks ..The scope of API 650 is
1.1 General
1.1.1 This standard establishes minimum requirements for material, design, fabrication, erection, and inspection for
vertical, cylindrical, aboveground, closed- and open-top, welded storage tanks in various sizes and capacities for
internal pressures approximating atmospheric pressure ....
1.1.2 This standard provides industry with tanks of adequate safety and reasonable economy for use in the storage of
petroleum, petroleum products,...

You may follow the stringent Inspection and test RT requirements of API 650 for a simple farm water tank also..But why not AWWA D100 Sec. 14.4 ??

Tim was so learned that he could name a
horse in nine languages: so ignorant that he bought a cow to ride on.
(BENJAMIN FRANKLIN )

You are not using any of Excel's capabilities.
Instead of using it as a drawing board, can you use the cell borders to draw the tank, with each shell plate having say 8 rows and 20 columns, and then put formulas in cells to change color or display numerically increasing values. You could put values in each cell representing the shell thickness with text color white so they won't show, and use conditional formatting to show various RT shots based on thickness, then formulas in cells with custom formatting to number the shots. A few macros would semi automate the process and perhaps the effort would pay off in a few projects.

I've got blocks drawn with the different numbers in them, then just copy where required on the shell layout detail.