We use both programs and from what I have been told by BuilderTrend support they don't offer anyway to export data into Sage 100 Contractor and back.  I have to say it is a pain manually entering change orders in 2 places to keep the accounting up to date.  For now, it is worth the time and expense to use BuilderTrend Scheduling, Change Orders, Messaging and Files functionality with Sage 100 Contractor.

We tried exporting and uploading and it didn't work.  What we have had best success with is copy and paste.   We set up the excel export from buildertrend timecards to match the entry for the payroll and can copy and paste the lines.

We also made sure all our cost codes had the same numbering so that when transfering over estimates or change orders it made it really easy to type in the number.   

We really like both systems and wish they would communicate better to avoid the double entry.