Using variables in file names during import/export

Question

I have 23 .csv files named as 0.csv, 1.csv....

I'd like to import those files one by one, perform some manipulation on the data and finally export it as "i+20".csv.

"i" is the variable which in my case goes from 0 to 22.

Answer 1

Use ToString

Do[
Export[yourPathToFile<>ToString[i+20]<>".csv", yourData[[i]]]
,{i,0,22}