Calculated item prototype on template with custom query mssql

[ivanpl82]

Hello,

I have an item prototype in a discovery rules using the mssql plugin which has the key bellow:

mssql.custom.query[,,,cpu_per_db,{#DBNAME}]

Now I want to get that value on a new item prototype calculated. So I set a new name, a new key for this new item, and set the next formula:

last(mssql.custom.query[,,,cpu_per_db,{#DBNAME}])*100

It's only an example, but I alway get the same error:

Cannot evaluate function "last("","","cpu_per_db","TEST]")": item "host1:mssql.custom.query[" does not exist.

TEST is the value of DBNAME.
The error shows me that it has troubles with quotes.
I tried several combinations but I always get the same error.

Another try:
- Formula: last("mssql.custom.query[,,,cpu_per_db,{#DBNAME}]")*100
- Error: Cannot evaluate function "last(,,cpu_per_db,{#DBNAME}])": item "host1:mssql.custom.query[" does not exist.

Doesn't get the value of DBNAME.

Another try:
- Formula: last("mssql.custom.query[",,,cpu_per_db,{#DBNAME}"]")*100
- Error: Cannot evaluate function "last(,,cpu_per_db,{#DBNAME}"])": item "host1:mssql.custom.query["" does not exist.

One more time:
- Formula: last(mssql.custom.query[",,,cpu_per_db,{#DBNAME}"])*100
- Error: Cannot evaluate function "last("","","cpu_per_db","TEST\\"]")": item "host1:mssql.custom.query["" does not exist.

And the finally test:
- Formula: last(mssql.custom.query[",,,cpu_per_db,{#DBNAME}"])*100
- Error: Cannot evaluate function "last("","","cpu_per_db","TEST"]")": item "host1:mssql.custom.query["" does not exist.

Is it possible to create an item calculated prototype according another item prototype?

Thank you in advance.