Subset dataframe filtered by specific name

Hi guys I'm new here so it's my first post, be gentle :D

I'm working with DNA sequences and after I have imported the .fasta file (using "readDNAStringSet") and converted the names & sequences into a separate R object with 7754 obs. & 2 variables (names, seq), I want to extract specific rows according their names into a new dataframe. As and example of what I mean, I have 10 names starting with "B07:" and 5 names starting with "B38:", I want to extract from these 15 names only those starting with "B*07:" and save them as a new dataframe for later saving into new .fasta file.

Does anybody have an Idea how I could achieve that?