Thanks for your help, I was actually forgetting about that which I had already used before in other cases. 
I have this working now and I will mark it as solved, but it would be interesting to have a loop instead of repeating this in 30 or 40 lines.
For future reference, this is the working code (clearly not optimized at all):
{
"Name": "Save Prods",
"CreationDate": "2020-9-14",
"Commands": [
{
"Command": "store",
"Target": "true",
"Value": "!errorignore"
},
{
"Command": "storeText",
"Target": "css=.breadcrumbs a:nth-child(2)",
"Value": "!csvLine"
},
{
"Command": "storeText",
"Target": "css=.breadcrumbs a:nth-child(3)",
"Value": "!csvLine"
},
{
"Command": "storeText",
"Target": "css=.breadcrumbs a:nth-child(4)",
"Value": "!csvLine"
},
{
"Command": "storeTitle",
"Target": "xpath=//*[@id=\"left-column\"]/h1",
"Value": "!csvLine"
},
{
"Command": "storeAttribute",
"Target": "css=.img-container>img@src",
"Value": "!csvLine"
},
{
"Command": "storeText",
"Target": "id=product-cod-des",
"Value": "!csvLine"
},
{
"Command": "storeText",
"Target": "xpath=//*[@id=\"details\"]/p",
"Value": "desc"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[0].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[1].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[2].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[3].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[4].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[5].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[6].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[7].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[8].trim();",
"Value": "!csvLine"
},
{
"Command": "executeScript_Sandbox",
"Target": "return ${desc}.split(\"\\n\")[9].trim();",
"Value": "!csvLine"
},
{
"Command": "csvSave",
"Target": "prods.csv",
"Value": ""
}
]
}