Hi I'm new to cryptogragraphy and have no idea how to do this. So i get a public key from a Putty session and it looks like this:

0x23,0xa69e43f72f1d8f07a6baae6ea0b0ce81cbe949345a0a5e307ae89e9cf58b20a17571af39e951faf61c45ef2ca9e21897eb9bc226473783ed9c3f6e30c4a84fa625373af96f41f8d9670484b52a33072eae6bb5433a2f00c672c20d7a03636a1b26af15b0d3ed376b9699e8653caa198637be88282333e8038bed63b9a2c6d179

by searching the Internet I found following Thread in which the same format appears, so I know that the first hex value is the exponent and the second value is the modulus. But i cound't find anything on how to use the two to get a simple public key. http://winscp.net/forum/viewtopic.php?t=5850

My Question is: How do I convert the key to a standard openssh fromat ergo base64?

hope someone can help.