Excel to text file transfer of data.

I have a data in excel sheet which I would like to convert into a text file. In the text file, the data format should be with the brackets and comma separated.

For example:
In excel sheet:

12 2 45 25
23 1 35 50
24 1 21 23



In text file the same data should be in the following format:

(12,2,45)[25]
(23,1,35)[50]
(24,1,21)[23]

The above is for one data set . In other data set, the brackets may change places for example:
(1,23)[12,34,56]

I have many data sets in which I would like to put brackets at the necessary places according to the requirement. Kindly help

Thanking you,
Ramanan