G4AON
With the Icom programming tool (CS-51) under digital\repeater list, find UK_DV_Nodes (or whatever is appropriate for USA simplex digital nodes).
You should find several. Add another as type “DV Repeater”, name it Shark, sub name Node, Repeater callsign of your callsignD (D being the last character), Gateway callsign of your callsignG, frequency 433.9000 (or whatever your Shark is), -DUP, Offset Freq 0.0000, Mode DV, tones blank, Use Yes, position is your lat/long.
73 Dave