Dynamics GP Developer

We recommend you to outsource Dynamics GP Dexterity programming to Dexterity Dynamics GP technology partner.
Your new custom tables often need to be joined with original GP tables. If you need good performance in integration projects - you may create SQL stored procedures and call them from your custom Dexterity add-on. All these objects (in the case of SQL Stored Procs, you have their proxies with declared parameters in Dex) are stored in your custom Dexterity dictionary, which you, as Dexterity developer produce out of Dynamics.dic dictionary with your custom objects in.
However consider the fact, that some of the forms might be already customized by other Dynamics GP add-ons and if this is the case, you will have to choose which alternate form to use. Having said that, we recommend you first to analyze if so-called Dexterity trigger could do the same job for you without altering the form itself.