List of temporary table columns (MySQL)

I need to get the column columns of some temporary table (MyISAM) in MySQL, like number column- name column. I need to know the number of columns with a specific name. In advance, I do not know what the number of columns is. I am using dynamic sql with some variables to create a temporary table.

I cannot use show columns...it because I cannot work with the results of this function. I cannot use INFORMATION_SCHEMA.COLUMNSbecause it does not contain columns of the temporary table.

Some ideas? Thanks in advance!