SAS simulate with random variable

1. Simulate C2*2 + C4

2. At each trial C4 is a set of random numbers between 0 and 1

3. C4 is selected based on C1=C3

   Table1
   C1 C2
   A 1
   A 2.3
   B 5
   B 0.7 C 8 D 1.6

   Table 2 C3 C4 A random B random C random D random

4. I tried to convert C1 C2 to arrays but am stuck at how to proceed with C1=C3 to get C4

5. How do I create a C4 array based on C1 and C3?

6. I can only think of hardcoding by defining each variable but hope to get advise on a better way