Como Cobrar 100 Escolaridad

I'm dealing with external program that is run from excel in the meddle of VBA script (program reads data from the .xls, makes some actions and puts data back to .xls).
And I need to wait the execution of the rest of the script till the program finishes all the actions.
I tried to work with the processes but failed as the external program have a continuously long process.
Tried to use a loops and wait procedures