You can use the New-RestoreDatabaseFromMark
cmdlet with or without specifying the mark. Leaving the mark empty is equivalent to last mark.
Microsoft Script Center focuses on teaching people how to use Windows PowerShell and VBScript to reduce time spent performing mundane tasks. Through script center you can find many PowerShell scripts and a few on BizTalk:
Read suggested related topics:
Another important place to find an extensive amount of BizTalk related articles is the TechNet Wiki itself. The best entry point is
BizTalk Server Resources on the TechNet Wiki.