If you’re setting up Multicurrency in GP with Management Reporter, the best guide I’ve found is from MS and you can find it at https://support.microsoft.com/en-us/kb/2986068.
Keep in mind, you need to be on the latest release of MR 2012. There were MC fixes in CU11 and the MS knee jerk reaction to MR issues is to insist that you are on the latest release. Given the volume of releases, that’s good advice anyway.