MATLAB Compiler SDK did not exist in R2009b. In R2009b, there were several different products, such as MATLAB Java Builder, and MATLAB Builder .NET . They were licensed separately from MATLAB.
If you do not currently have a license for the appropriate Builder product, then to use it with R2009b, you would need to purchase MATLAB Compiler SDK at the current release, and that product key would then authorize you to run the older products. You might need some assistance from Mathworks Support to get the proper keys. It would probably be a good idea to cross-check with Sales to be sure that this is the correct practice.