How to give While loop in script component in data flow task in SSIS?

Hi,

I used look up transformation to get one- "MAX_NO_COVERAGES" from look up table, then using that column "MAX_NO_COVERAGES" column, I have to get another column "INDEX_TEMP" and to calculate this column "INDEX_TEMP", I have to use while loop. 

Logic is as below: 

I = 0

DO WHILE (I <= MAX_NO_COVERAGES)

         I = I + 1
         INDEX_TEMP = STRVAL(INDEX) + "-" + STRVAL(I)

__________

where INDEX is one of input field of table. and MAX_NO_COVERAGES has value of 1 to 4.

Please tell me how can I apply this while loop in data flow task of SSIS? Do I need to use script component or derived column? Please give me script - code of script component if I need to use it. 

Thank you so much in advance for help.

Vicky