Hi experts

I have a set of velocity speeds for soils and rocks and I'm using an index and match formula for these speeds for data I'm importing. The formula is

=INDEX(H28:H45,SUMPRODUCT(--(I28:I45<=D7)*(J28:J45>=D7),ROW(I28:I45))-ROW(28:28)+1)

The reference table H28-J45 is shown below:

Soft CLAY 40 75
Stiff CLAY 75 135
Loose SAND 135 240
Dense SAND & GRAVEL 240 355
Residual Soil 355 600
Metamorphic and Igneous rock
RQDa 0 500
RQDb 600 760
RQDc 760 1500
RQDd 1500 2500
RQDe 2500 3400
Basement 3400 3600
Porous & saturated sandstone 800 1800
Limestone 2000 3300
Chalk 1100 1300
Granite 2500 3300
Basalt 2800 3400
Gneiss 2700 3200

The formula works....unless there are overlapping velocities. i.e if I'm returning a speed of 2900 the index & matched rock type could be Limestone, Granite, Basalt and Gneiss resulting in me returning an error. Is it possible for excel to somehow Concatenate these returned values into 1 cell or am I stuck with only being able to return one result?

Thank you for your time!