Printing the lines of the string with highest value

Shell Programming and Scripting
1

Please help .

The script need to first grep for all lines with "C:" as it contains a value

Here the value is 0

1,00:  This , is a good script  c:0

and then give output of the lines with top 3 highest value for c:

1,00:  This , is a nice script  c:9999
1,00:  This , is a good  script  c:9998
1,00:  This , is a  cool  script  c:9000
1,00:  This , is a   fun   script  c:12

So the output should be

1,00:  This , is a nice script  c:9999
 1,00:  This , is a good  script  c:9998
 1,00:  This , is a  cool  script  c:9000

---------- Post updated at 01:31 AM ---------- Previous

2 
sort -t: -nr -k3 input.txt | head -3
3

No that didnt work and i think you misunderstood

Not all lines in the file contain the word "c:" and the position of the word would also vary on the line , hence first c: needs to be grepped separately from the file and then the top 10 highest value for it should be printed for it

eg
1,00: This , is a nice script c:9999
1,00: This , is a good script c:9998
1,00: This , is a cool script c:9000
1,00: This , is a fun script c:12

So the output should be

1,00: This , is a nice script c:9999
1,00: This , is a good script c:9998
1,00: This , is a cool script c:9000

4 
awk '/c:/' infile |sort -t: -nr -k3  | head -3

grep "c:"  infile |sort -t: -nr -k3  | head -3