they almost all use the same .sav fileformat. problem is that they usually have like different headers or the composition of the sav file is somewhat different so they don't actually get recognized between different emulators.
i do know that no$gba on pc has an import feature that does, somehow, take gpsp game saves. but it doesnt always work right either.
may i ask which game it is that troubles you? I guess theres some part of a game that freezes and you hope to skip it in a different emulator, yes?