I think you mean importing and exporting models. Extracting them just means you took them out of the .SGA in their raw .RGM format.
Anyways, the CoH1 import and export tools are the only way.
http://forums.relicnews.com/showthread.php?248913-TOOL-RGM-Importer-v0-24-Works-for-NEW-versions-of-3D-max!
Some models simply will not import while others require painstaking work to get into a usable state.
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#Steam AliasWL%Streak
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